61891980 has 24 divisors (see below), whose sum is σ = 173297712. Its totient is φ = 16504512.

The previous prime is 61891957. The next prime is 61892029. The reversal of 61891980 is 8919816.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 515707 + ... + 515826.

It is an arithmetic number, because the mean of its divisors is an integer number (7220738).

Almost surely, 2^61891980 is an apocalyptic number.

61891980 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

61891980 is an abundant number, since it is smaller than the sum of its proper divisors (111405732).

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

61891980 is a wasteful number, since it uses less digits than its factorization.

61891980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1031545 (or 1031543 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 42.

The square root of 61891980 is about 7867.1456068895. The cubic root of 61891980 is about 395.5591717302.

The spelling of 61891980 in words is "sixty-one million, eight hundred ninety-one thousand, nine hundred eighty".