140642640 has 120 divisors (see below), whose sum is σ = 474943560. Its totient is φ = 37297152.

The previous prime is 140642639. The next prime is 140642647. The reversal of 140642640 is 46246041.

140642640 is a `hidden beast` number, since 14 + 0 + 6 + 4 + 2 + 640 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 13133376 + 127509264 = 3624^2 + 11292^2 .

It is a tau number, because it is divible by the number of its divisors (120).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (140642647) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 164454 + ... + 165306.

It is an arithmetic number, because the mean of its divisors is an integer number (3957863).

Almost surely, 2^140642640 is an apocalyptic number.

140642640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 140642640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (237471780).

140642640 is an abundant number, since it is smaller than the sum of its proper divisors (334300920).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

140642640 is a wasteful number, since it uses less digits than its factorization.

140642640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1101 (or 1092 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 27.

The square root of 140642640 is about 11859.2849700140. The cubic root of 140642640 is about 520.0426986634.

Adding to 140642640 its reverse (46246041), we get a palindrome (186888681).

The spelling of 140642640 in words is "one hundred forty million, six hundred forty-two thousand, six hundred forty".