61990631 has 4 divisors (see below), whose sum is σ = 62139000. Its totient is φ = 61842264.

The previous prime is 61990627. The next prime is 61990633. The reversal of 61990631 is 13609916.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 61990631 - 2² = 61990627 is a prime.

It is a super-2 number, since 2×61990631² = 7685676663556322, which contains 22 as substring.

It is a Duffinian number.

It is a zygodrome in base 5.

It is a junction number, because it is equal to n+sod(n) for n = 61990591 and 61990600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61990633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 73556 + ... + 74393.

It is an arithmetic number, because the mean of its divisors is an integer number (15534750).

Almost surely, 2^61990631 is an apocalyptic number.

61990631 is a deficient number, since it is larger than the sum of its proper divisors (148369).

61990631 is a wasteful number, since it uses less digits than its factorization.

61990631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148368.

The product of its (nonzero) digits is 8748, while the sum is 35.

The square root of 61990631 is about 7873.4129194397. The cubic root of 61990631 is about 395.7692236807.

The spelling of 61990631 in words is "sixty-one million, nine hundred ninety thousand, six hundred thirty-one".