61991930 has 96 divisors (see below), whose sum is σ = 151224192. Its totient is φ = 17804160.

The previous prime is 61991899. The next prime is 61991987. The reversal of 61991930 is 3919916.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 109829 + ... + 110391.

It is an arithmetic number, because the mean of its divisors is an integer number (1575252).

Almost surely, 2^61991930 is an apocalyptic number.

61991930 is an abundant number, since it is smaller than the sum of its proper divisors (89232262).

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

61991930 is a wasteful number, since it uses less digits than its factorization.

61991930 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 612 (or 601 counting only the distinct ones).

The product of its (nonzero) digits is 13122, while the sum is 38.

The square root of 61991930 is about 7873.4954118231. The cubic root of 61991930 is about 395.7719880803.

The spelling of 61991930 in words is "sixty-one million, nine hundred ninety-one thousand, nine hundred thirty".