51531021545 has 16 divisors (see below), whose sum is σ = 62862085200. Its totient is φ = 40541817600.

The previous prime is 51531021539. The next prime is 51531021547. The reversal of 51531021545 is 54512013515.

It can be written as a sum of positive squares in 8 ways, for example, as 961806169 + 50569215376 = 31013^2 + 224876^2 .

It is not a de Polignac number, because 51531021545 - 2²⁴ = 51514244329 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51531021547) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2291255 + ... + 2313635.

It is an arithmetic number, because the mean of its divisors is an integer number (3928880325).

Almost surely, 2^51531021545 is an apocalyptic number.

It is an amenable number.

51531021545 is a deficient number, since it is larger than the sum of its proper divisors (11331063655).

51531021545 is a wasteful number, since it uses less digits than its factorization.

51531021545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29996.

The product of its (nonzero) digits is 15000, while the sum is 32.

The spelling of 51531021545 in words is "fifty-one billion, five hundred thirty-one million, twenty-one thousand, five hundred forty-five".