51810240402 has 48 divisors (see below), whose sum is σ = 118363433760. Its totient is φ = 16333474176.

The previous prime is 51810240389. The next prime is 51810240409. The reversal of 51810240402 is 20404201815.

51810240402 is a `hidden beast` number, since 5 + 1 + 8 + 10 + 240 + 402 = 666.

It is not an unprimeable number, because it can be changed into a prime (51810240409) 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, 75073 + ... + 330539.

It is an arithmetic number, because the mean of its divisors is an integer number (2465904870).

Almost surely, 2^51810240402 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51810240402, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (59181716880).

51810240402 is an abundant number, since it is smaller than the sum of its proper divisors (66553193358).

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

51810240402 is a wasteful number, since it uses less digits than its factorization.

51810240402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 256087 (or 256084 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 27.

The spelling of 51810240402 in words is "fifty-one billion, eight hundred ten million, two hundred forty thousand, four hundred two".