61915631 has 4 divisors (see below), whose sum is σ = 61960272. Its totient is φ = 61870992.

The previous prime is 61915627. The next prime is 61915639. The reversal of 61915631 is 13651916.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 61915631 - 2² = 61915627 is a prime.

It is a super-2 number, since 2×61915631² = 7667090724256322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61915639) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20171 + ... + 23036.

It is an arithmetic number, because the mean of its divisors is an integer number (15490068).

Almost surely, 2^61915631 is an apocalyptic number.

61915631 is a deficient number, since it is larger than the sum of its proper divisors (44641).

61915631 is a wasteful number, since it uses less digits than its factorization.

61915631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44640.

The product of its digits is 4860, while the sum is 32.

The square root of 61915631 is about 7868.6486133262. The cubic root of 61915631 is about 395.6095507861.

The spelling of 61915631 in words is "sixty-one million, nine hundred fifteen thousand, six hundred thirty-one".