61921791 has 12 divisors (see below), whose sum is σ = 89511240. Its totient is φ = 41249520.

The previous prime is 61921789. The next prime is 61921879. The reversal of 61921791 is 19712916.

It is not a de Polignac number, because 61921791 - 2¹ = 61921789 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61921721) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19600 + ... + 22538.

It is an arithmetic number, because the mean of its divisors is an integer number (7459270).

Almost surely, 2^61921791 is an apocalyptic number.

61921791 is a deficient number, since it is larger than the sum of its proper divisors (27589449).

61921791 is a wasteful number, since it uses less digits than its factorization.

61921791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5286 (or 5283 counting only the distinct ones).

The product of its digits is 6804, while the sum is 36.

The square root of 61921791 is about 7869.0400303976. The cubic root of 61921791 is about 395.6226701120.

The spelling of 61921791 in words is "sixty-one million, nine hundred twenty-one thousand, seven hundred ninety-one".