61655531 has 8 divisors (see below), whose sum is σ = 71658240. Its totient is φ = 51951528.

The previous prime is 61655527. The next prime is 61655533. The reversal of 61655531 is 13555616.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 61655531 - 2² = 61655527 is a prime.

It is a super-2 number, since 2×61655531² = 7602809005783922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61655533) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 74231 + ... + 75056.

It is an arithmetic number, because the mean of its divisors is an integer number (8957280).

Almost surely, 2^61655531 is an apocalyptic number.

61655531 is a deficient number, since it is larger than the sum of its proper divisors (10002709).

61655531 is a wasteful number, since it uses less digits than its factorization.

61655531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149353.

The product of its digits is 13500, while the sum is 32.

The square root of 61655531 is about 7852.1036034938. The cubic root of 61655531 is about 395.0548041248.

The spelling of 61655531 in words is "sixty-one million, six hundred fifty-five thousand, five hundred thirty-one".