2157517844 has 12 divisors (see below), whose sum is σ = 3814581204. Its totient is φ = 1067637504.

The previous prime is 2157517837. The next prime is 2157517891. The reversal of 2157517844 is 4487157512.

It can be written as a sum of positive squares in 2 ways, for example, as 1463827600 + 693690244 = 38260^2 + 26338^2 .

It is a hoax number, since the sum of its digits (44) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 2157517795 and 2157517804.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2779919 + ... + 2780694.

It is an arithmetic number, because the mean of its divisors is an integer number (317881767).

Almost surely, 2^2157517844 is an apocalyptic number.

It is an amenable number.

2157517844 is a deficient number, since it is larger than the sum of its proper divisors (1657063360).

2157517844 is a wasteful number, since it uses less digits than its factorization.

2157517844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5560714 (or 5560712 counting only the distinct ones).

The product of its digits is 313600, while the sum is 44.

The square root of 2157517844 is about 46449.0887316425. The cubic root of 2157517844 is about 1292.1654721016.

The spelling of 2157517844 in words is "two billion, one hundred fifty-seven million, five hundred seventeen thousand, eight hundred forty-four".