61881979 has 4 divisors (see below), whose sum is σ = 61904584. Its totient is φ = 61859376.

The previous prime is 61881977. The next prime is 61882003. The reversal of 61881979 is 97918816.

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 61881979 - 2¹ = 61881977 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (61881971) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6522 + ... + 12895.

It is an arithmetic number, because the mean of its divisors is an integer number (15476146).

Almost surely, 2^61881979 is an apocalyptic number.

61881979 is a deficient number, since it is larger than the sum of its proper divisors (22605).

61881979 is a wasteful number, since it uses less digits than its factorization.

61881979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22604.

The product of its digits is 217728, while the sum is 49.

The square root of 61881979 is about 7866.5099631285. The cubic root of 61881979 is about 395.5378647134.

The spelling of 61881979 in words is "sixty-one million, eight hundred eighty-one thousand, nine hundred seventy-nine".