51205249391986 has 32 divisors (see below), whose sum is σ = 82732343189760. Its totient is φ = 23690556597456.

The previous prime is 51205249391969. The next prime is 51205249392109. The reversal of 51205249391986 is 68919394250215.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 85891545 + ... + 86485651.

It is an arithmetic number, because the mean of its divisors is an integer number (2585385724680).

Almost surely, 2^{51205249391986} is an apocalyptic number.

51205249391986 is a deficient number, since it is larger than the sum of its proper divisors (31527093797774).

51205249391986 is a wasteful number, since it uses less digits than its factorization.

51205249391986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 646918.

The product of its (nonzero) digits is 41990400, while the sum is 64.

The spelling of 51205249391986 in words is "fifty-one trillion, two hundred five billion, two hundred forty-nine million, three hundred ninety-one thousand, nine hundred eighty-six".