1401387640 has 32 divisors (see below), whose sum is σ = 3154398480. Its totient is φ = 560328192.

The previous prime is 1401387623. The next prime is 1401387641. The reversal of 1401387640 is 467831041.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 1401387596 and 1401387605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1401387641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 121984 + ... + 132976.

Almost surely, 2^1401387640 is an apocalyptic number.

1401387640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1401387640 is an abundant number, since it is smaller than the sum of its proper divisors (1753010840).

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

1401387640 is a wasteful number, since it uses less digits than its factorization.

1401387640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14191 (or 14187 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 34.

The square root of 1401387640 is about 37435.1123946490. The cubic root of 1401387640 is about 1119.0584242072.

The spelling of 1401387640 in words is "one billion, four hundred one million, three hundred eighty-seven thousand, six hundred forty".