51567281820 has 72 divisors (see below), whose sum is σ = 156769376400. Its totient is φ = 13720627200.

The previous prime is 51567281783. The next prime is 51567281839. The reversal of 51567281820 is 2818276515.

51567281820 is a `hidden beast` number, since 5 + 1 + 567 + 2 + 8 + 1 + 82 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 238206 + ... + 399845.

It is an arithmetic number, because the mean of its divisors is an integer number (2177352450).

Almost surely, 2^51567281820 is an apocalyptic number.

It is an amenable number.

51567281820 is an abundant number, since it is smaller than the sum of its proper divisors (105202094580).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51567281820 is a wasteful number, since it uses less digits than its factorization.

51567281820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 638515 (or 638510 counting only the distinct ones).

The product of its (nonzero) digits is 268800, while the sum is 45.

The spelling of 51567281820 in words is "fifty-one billion, five hundred sixty-seven million, two hundred eighty-one thousand, eight hundred twenty".