1918837521 has 12 divisors (see below), whose sum is σ = 2782699920. Its totient is φ = 1274127000.

The previous prime is 1918837517. The next prime is 1918837541. The reversal of 1918837521 is 1257388191.

1918837521 is a `hidden beast` number, since 1 + 91 + 8 + 8 + 37 + 521 = 666.

It is not a de Polignac number, because 1918837521 - 2² = 1918837517 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1918837511) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 422451 + ... + 426968.

It is an arithmetic number, because the mean of its divisors is an integer number (231891660).

Almost surely, 2^1918837521 is an apocalyptic number.

It is an amenable number.

1918837521 is a deficient number, since it is larger than the sum of its proper divisors (863862399).

1918837521 is a wasteful number, since it uses less digits than its factorization.

1918837521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 849676 (or 849673 counting only the distinct ones).

The product of its digits is 120960, while the sum is 45.

The square root of 1918837521 is about 43804.5376759075. The cubic root of 1918837521 is about 1242.6421119807.

The spelling of 1918837521 in words is "one billion, nine hundred eighteen million, eight hundred thirty-seven thousand, five hundred twenty-one".