61998881 has 24 divisors (see below), whose sum is σ = 79279680. Its totient is φ = 47354112.

The previous prime is 61998877. The next prime is 61998883. The reversal of 61998881 is 18889916.

It is a happy number.

It is not a de Polignac number, because 61998881 - 2² = 61998877 is a prime.

It is a super-2 number, since 2×61998881² = 7687722490504322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61998883) 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 23 ways as a sum of consecutive naturals, for example, 37631 + ... + 39243.

It is an arithmetic number, because the mean of its divisors is an integer number (3303320).

Almost surely, 2^61998881 is an apocalyptic number.

It is an amenable number.

61998881 is a deficient number, since it is larger than the sum of its proper divisors (17280799).

61998881 is a wasteful number, since it uses less digits than its factorization.

61998881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1673 (or 1656 counting only the distinct ones).

The product of its digits is 248832, while the sum is 50.

The square root of 61998881 is about 7873.9368171201. The cubic root of 61998881 is about 395.7867798351.

The spelling of 61998881 in words is "sixty-one million, nine hundred ninety-eight thousand, eight hundred eighty-one".