51531506 has 16 divisors (see below), whose sum is σ = 85275288. Its totient is φ = 23203200.

The previous prime is 51531451. The next prime is 51531511. The reversal of 51531506 is 60513515.

51531506 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 30747025 + 20784481 = 5545^2 + 4559^2 .

It is a super-2 number, since 2×51531506² = 5310992221256072, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23105 + ... + 25236.

Almost surely, 2^51531506 is an apocalyptic number.

51531506 is a deficient number, since it is larger than the sum of its proper divisors (33743782).

51531506 is a wasteful number, since it uses less digits than its factorization.

51531506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48397.

The product of its (nonzero) digits is 2250, while the sum is 26.

The square root of 51531506 is about 7178.5448386146. The cubic root of 51531506 is about 372.1267970658.

Subtracting 51531506 from its reverse (60513515), we obtain a square (8982009 = 2997²).

The spelling of 51531506 in words is "fifty-one million, five hundred thirty-one thousand, five hundred six".