61931531 has 8 divisors (see below), whose sum is σ = 63564384. Its totient is φ = 60318720.

The previous prime is 61931491. The next prime is 61931537. The reversal of 61931531 is 13513916.

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 61931531 - 2²² = 57737227 is a prime.

It is a super-2 number, since 2×61931531² = 7671029064007922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 61931494 and 61931503.

It is not an unprimeable number, because it can be changed into a prime (61931537) 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, 1355 + ... + 11211.

It is an arithmetic number, because the mean of its divisors is an integer number (7945548).

Almost surely, 2^61931531 is an apocalyptic number.

61931531 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

61931531 is a deficient number, since it is larger than the sum of its proper divisors (1632853).

61931531 is a wasteful number, since it uses less digits than its factorization.

61931531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10021.

The product of its digits is 2430, while the sum is 29.

The square root of 61931531 is about 7869.6588871437. The cubic root of 61931531 is about 395.6434122058.

The spelling of 61931531 in words is "sixty-one million, nine hundred thirty-one thousand, five hundred thirty-one".