61155681 has 8 divisors (see below), whose sum is σ = 86337504. Its totient is φ = 38372160.

The previous prime is 61155671. The next prime is 61155701. The reversal of 61155681 is 18655116.

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

It is not a de Polignac number, because 61155681 - 2⁶ = 61155617 is a prime.

It is a super-2 number, since 2×61155681² = 7480034637147522, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (61155631) 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, 599515 + ... + 599616.

It is an arithmetic number, because the mean of its divisors is an integer number (10792188).

Almost surely, 2^61155681 is an apocalyptic number.

It is an amenable number.

61155681 is a deficient number, since it is larger than the sum of its proper divisors (25181823).

61155681 is a wasteful number, since it uses less digits than its factorization.

61155681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1199151.

The product of its digits is 7200, while the sum is 33.

The square root of 61155681 is about 7820.2097797949. The cubic root of 61155681 is about 393.9843178758.

The spelling of 61155681 in words is "sixty-one million, one hundred fifty-five thousand, six hundred eighty-one".