61881538 has 24 divisors (see below), whose sum is σ = 96795972. Its totient is φ = 29666304.

The previous prime is 61881529. The next prime is 61881557. The reversal of 61881538 is 83518816.

It can be written as a sum of positive squares in 6 ways, for example, as 46881409 + 15000129 = 6847^2 + 3873^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 61881538.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 265470 + ... + 265702.

Almost surely, 2^61881538 is an apocalyptic number.

61881538 is a deficient number, since it is larger than the sum of its proper divisors (34914434).

61881538 is a wasteful number, since it uses less digits than its factorization.

61881538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 406 (or 369 counting only the distinct ones).

The product of its digits is 46080, while the sum is 40.

The square root of 61881538 is about 7866.4819328592. The cubic root of 61881538 is about 395.5369251151.

The spelling of 61881538 in words is "sixty-one million, eight hundred eighty-one thousand, five hundred thirty-eight".