61991656 has 24 divisors (see below), whose sum is σ = 123478470. Its totient is φ = 29171456.

The previous prime is 61991641. The next prime is 61991659. The reversal of 61991656 is 65619916.

It can be written as a sum of positive squares in 3 ways, for example, as 61936900 + 54756 = 7870^2 + 234^2 .

It is not an unprimeable number, because it can be changed into a prime (61991659) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11095 + ... + 15718.

Almost surely, 2^61991656 is an apocalyptic number.

It is an amenable number.

61991656 is a deficient number, since it is larger than the sum of its proper divisors (61486814).

61991656 is a wasteful number, since it uses less digits than its factorization.

61991656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26853 (or 26832 counting only the distinct ones).

The product of its digits is 87480, while the sum is 43.

The square root of 61991656 is about 7873.4780116541. The cubic root of 61991656 is about 395.7714049846.

The spelling of 61991656 in words is "sixty-one million, nine hundred ninety-one thousand, six hundred fifty-six".