51890540645 has 6 divisors (see below), whose sum is σ = 62269260018. Its totient is φ = 41512025024.

The previous prime is 51890540633. The next prime is 51890540657. The reversal of 51890540645 is 54604509815.

It is an interprime number because it is at equal distance from previous prime (51890540633) and next prime (51890540657).

It can be written as a sum of positive squares in 3 ways, for example, as 1800964 + 51888739681 = 1342^2 + 227791^2 .

It is not a de Polignac number, because 51890540645 - 2⁸ = 51890540389 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 51890540645.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 458429 + ... + 560301.

It is an arithmetic number, because the mean of its divisors is an integer number (10378210003).

Almost surely, 2^51890540645 is an apocalyptic number.

It is an amenable number.

51890540645 is a deficient number, since it is larger than the sum of its proper divisors (10378719373).

51890540645 is an frugal number, since it uses more digits than its factorization.

51890540645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203751 (or 101878 counting only the distinct ones).

The product of its (nonzero) digits is 864000, while the sum is 47.

The spelling of 51890540645 in words is "fifty-one billion, eight hundred ninety million, five hundred forty thousand, six hundred forty-five".