61981956 has 48 divisors (see below), whose sum is σ = 165047680. Its totient is φ = 20100960.

The previous prime is 61981943. The next prime is 61981957. The reversal of 61981956 is 65918916.

It is not an unprimeable number, because it can be changed into a prime (61981957) 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 in 15 ways as a sum of consecutive naturals, for example, 3760 + ... + 11751.

Almost surely, 2^61981956 is an apocalyptic number.

It is an amenable number.

61981956 is an abundant number, since it is smaller than the sum of its proper divisors (103065724).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61981956 is a wasteful number, since it uses less digits than its factorization.

61981956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15561 (or 15553 counting only the distinct ones).

The product of its digits is 116640, while the sum is 45.

The square root of 61981956 is about 7872.8619954880. The cubic root of 61981956 is about 395.7507614382.

The spelling of 61981956 in words is "sixty-one million, nine hundred eighty-one thousand, nine hundred fifty-six".