61155631 has 2 divisors, whose sum is σ = 61155632. Its totient is φ = 61155630.

The previous prime is 61155617. The next prime is 61155667. The reversal of 61155631 is 13655116.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 61155631 - 2⁵ = 61155599 is a prime.

It is a super-2 number, since 2×61155631² = 7480022406016322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 61155631.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61155671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30577815 + 30577816.

It is an arithmetic number, because the mean of its divisors is an integer number (30577816).

Almost surely, 2^61155631 is an apocalyptic number.

61155631 is a deficient number, since it is larger than the sum of its proper divisors (1).

61155631 is an equidigital number, since it uses as much as digits as its factorization.

61155631 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2700, while the sum is 28.

The square root of 61155631 is about 7820.2065829491. The cubic root of 61155631 is about 393.9842105038.

The spelling of 61155631 in words is "sixty-one million, one hundred fifty-five thousand, six hundred thirty-one".