51523581 has 8 divisors (see below), whose sum is σ = 70914304. Its totient is φ = 33240960.

The previous prime is 51523553. The next prime is 51523621. The reversal of 51523581 is 18532515.

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

It is not a de Polignac number, because 51523581 - 2¹⁹ = 50999293 is a prime.

It is a super-2 number, since 2×51523581² = 5309358798127122, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51523501) 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, 276916 + ... + 277101.

It is an arithmetic number, because the mean of its divisors is an integer number (8864288).

Almost surely, 2^51523581 is an apocalyptic number.

It is an amenable number.

51523581 is a deficient number, since it is larger than the sum of its proper divisors (19390723).

51523581 is a wasteful number, since it uses less digits than its factorization.

51523581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 554051.

The product of its digits is 6000, while the sum is 30.

The square root of 51523581 is about 7177.9928252959. The cubic root of 51523581 is about 372.1077197008.

The spelling of 51523581 in words is "fifty-one million, five hundred twenty-three thousand, five hundred eighty-one".