51660091 has 8 divisors (see below), whose sum is σ = 59180544. Its totient is φ = 44174760.

The previous prime is 51660073. The next prime is 51660137. The reversal of 51660091 is 19006615.

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

It is not a de Polignac number, because 51660091 - 2⁷ = 51659963 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51663091) 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, 5545 + ... + 11578.

It is an arithmetic number, because the mean of its divisors is an integer number (7397568).

Almost surely, 2^51660091 is an apocalyptic number.

51660091 is a deficient number, since it is larger than the sum of its proper divisors (7520453).

51660091 is a wasteful number, since it uses less digits than its factorization.

51660091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17561.

The product of its (nonzero) digits is 1620, while the sum is 28.

The square root of 51660091 is about 7187.4954608681. The cubic root of 51660091 is about 372.4360588716.

The spelling of 51660091 in words is "fifty-one million, six hundred sixty thousand, ninety-one".