61631 has 2 divisors, whose sum is σ = 61632. Its totient is φ = 61630.

The previous prime is 61627. The next prime is 61637. The reversal of 61631 is 13616.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 61631 - 2² = 61627 is a prime.

It is a super-2 number, since 2×61631² = 7596760322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30815 + 30816.

It is an arithmetic number, because the mean of its divisors is an integer number (30816).

2⁶¹⁶³¹ is an apocalyptic number.

61631 is a deficient number, since it is larger than the sum of its proper divisors (1).

61631 is an equidigital number, since it uses as much as digits as its factorization.

61631 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108, while the sum is 17.

The square root of 61631 is about 248.2559163444. The cubic root of 61631 is about 39.5002403446.

The spelling of 61631 in words is "sixty-one thousand, six hundred thirty-one".