51693551 has 24 divisors (see below), whose sum is σ = 65757024. Its totient is φ = 39761280.

The previous prime is 51693541. The next prime is 51693553. The reversal of 51693551 is 15539615.

It is a happy number.

It is not a de Polignac number, because 51693551 - 2¹⁸ = 51431407 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51693553) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 43181 + ... + 44361.

It is an arithmetic number, because the mean of its divisors is an integer number (2739876).

Almost surely, 2^51693551 is an apocalyptic number.

51693551 is a deficient number, since it is larger than the sum of its proper divisors (14063473).

51693551 is a wasteful number, since it uses less digits than its factorization.

51693551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1251 (or 1238 counting only the distinct ones).

The product of its digits is 20250, while the sum is 35.

The square root of 51693551 is about 7189.8227377314. The cubic root of 51693551 is about 372.5164498839.

The spelling of 51693551 in words is "fifty-one million, six hundred ninety-three thousand, five hundred fifty-one".