61929921 has 8 divisors (see below), whose sum is σ = 83167840. Its totient is φ = 40989312.

The previous prime is 61929859. The next prime is 61929943. The reversal of 61929921 is 12992916.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 61929921 - 2¹⁰ = 61928897 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 61929921.

It is not an unprimeable number, because it can be changed into a prime (61929991) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 73840 + ... + 74673.

It is an arithmetic number, because the mean of its divisors is an integer number (10395980).

Almost surely, 2^61929921 is an apocalyptic number.

It is an amenable number.

61929921 is a deficient number, since it is larger than the sum of its proper divisors (21237919).

61929921 is a wasteful number, since it uses less digits than its factorization.

61929921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148655.

The product of its digits is 17496, while the sum is 39.

The square root of 61929921 is about 7869.5565948788. The cubic root of 61929921 is about 395.6399837345.

The spelling of 61929921 in words is "sixty-one million, nine hundred twenty-nine thousand, nine hundred twenty-one".