61031631 has 16 divisors (see below), whose sum is σ = 84389760. Its totient is φ = 39187680.

The previous prime is 61031617. The next prime is 61031651. The reversal of 61031631 is 13613016.

It is not a de Polignac number, because 61031631 - 2⁵ = 61031599 is a prime.

It is a super-2 number, since 2×61031631² = 7449719965040322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 61031598 and 61031607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61031651) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 55396 + ... + 56486.

It is an arithmetic number, because the mean of its divisors is an integer number (5274360).

Almost surely, 2^61031631 is an apocalyptic number.

61031631 is a deficient number, since it is larger than the sum of its proper divisors (23358129).

61031631 is a wasteful number, since it uses less digits than its factorization.

61031631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1766.

The product of its (nonzero) digits is 324, while the sum is 21.

The square root of 61031631 is about 7812.2743807421. The cubic root of 61031631 is about 393.7177477236.

Adding to 61031631 its reverse (13613016), we get a palindrome (74644647).

The spelling of 61031631 in words is "sixty-one million, thirty-one thousand, six hundred thirty-one".