615381538464 has 960 divisors, whose sum is σ = 2335931136000. Its totient is φ = 154278328320.

The previous prime is 615381538451. The next prime is 615381538483. The reversal of 615381538464 is 464835183516.

It is a happy number.

615381538464 is a `hidden beast` number, since 6 + 1 + 53 + 81 + 53 + 8 + 464 = 666.

It is a super-2 number, since 2×615381538464² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 615381538464.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 1233229287 + ... + 1233229785.

It is an arithmetic number, because the mean of its divisors is an integer number (2433261600).

Almost surely, 2^615381538464 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 615381538464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1167965568000).

615381538464 is an abundant number, since it is smaller than the sum of its proper divisors (1720549597536).

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

615381538464 is a wasteful number, since it uses less digits than its factorization.

615381538464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 743 (or 726 counting only the distinct ones).

The product of its digits is 8294400, while the sum is 54.

The spelling of 615381538464 in words is "six hundred fifteen billion, three hundred eighty-one million, five hundred thirty-eight thousand, four hundred sixty-four".