61213140 has 36 divisors (see below), whose sum is σ = 185680404. Its totient is φ = 16323456.

The previous prime is 61213091. The next prime is 61213151. The reversal of 61213140 is 4131216.

It is a happy number.

61213140 is a `hidden beast` number, since 612 + 13 + 1 + 40 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 34152336 + 27060804 = 5844^2 + 5202^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 169857 + ... + 170216.

It is an arithmetic number, because the mean of its divisors is an integer number (5157789).

Almost surely, 2^61213140 is an apocalyptic number.

61213140 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

61213140 is an abundant number, since it is smaller than the sum of its proper divisors (124467264).

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

61213140 is a wasteful number, since it uses less digits than its factorization.

61213140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340088 (or 340083 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 61213140 is about 7823.8826678319. The cubic root of 61213140 is about 394.1076689606.

Adding to 61213140 its reverse (4131216), we get a palindrome (65344356).

It can be divided in two parts, 612131 and 40, that added together give a triangular number (612171 = T₁₁₀₆).

The spelling of 61213140 in words is "sixty-one million, two hundred thirteen thousand, one hundred forty".