51215421240 has 96 divisors (see below), whose sum is σ = 166479066000. Its totient is φ = 13655070720.

The previous prime is 51215421193. The next prime is 51215421241. The reversal of 51215421240 is 4212451215.

It is a happy number.

51215421240 is a `hidden beast` number, since 5 + 1 + 215 + 421 + 24 + 0 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51215421241) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3264936 + ... + 3280584.

Almost surely, 2^51215421240 is an apocalyptic number.

It is an amenable number.

51215421240 is an abundant number, since it is smaller than the sum of its proper divisors (115263644760).

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

51215421240 is a wasteful number, since it uses less digits than its factorization.

51215421240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24757 (or 24750 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 27.

Adding to 51215421240 its reverse (4212451215), we get a palindrome (55427872455).

The spelling of 51215421240 in words is "fifty-one billion, two hundred fifteen million, four hundred twenty-one thousand, two hundred forty".