51421449618 has 384 divisors, whose sum is σ = 155793093120. Its totient is φ = 12256358400.

The previous prime is 51421449523. The next prime is 51421449619. The reversal of 51421449618 is 81694412415.

51421449618 is a `hidden beast` number, since 5 + 1 + 4 + 21 + 4 + 4 + 9 + 618 = 666.

It is not an unprimeable number, because it can be changed into a prime (51421449619) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 31878580 + ... + 31880192.

It is an arithmetic number, because the mean of its divisors is an integer number (405711180).

Almost surely, 2^51421449618 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51421449618, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (77896546560).

51421449618 is an abundant number, since it is smaller than the sum of its proper divisors (104371643502).

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

51421449618 is a wasteful number, since it uses less digits than its factorization.

51421449618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1711 (or 1694 counting only the distinct ones).

The product of its digits is 276480, while the sum is 45.

The spelling of 51421449618 in words is "fifty-one billion, four hundred twenty-one million, four hundred forty-nine thousand, six hundred eighteen".