2155639851 has 16 divisors (see below), whose sum is σ = 3361622400. Its totient is φ = 1361456424.

The previous prime is 2155639847. The next prime is 2155639891. The reversal of 2155639851 is 1589365512.

2155639851 is a `hidden beast` number, since 2 + 1 + 5 + 5 + 639 + 8 + 5 + 1 = 666.

It is not a de Polignac number, because 2155639851 - 2² = 2155639847 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2155639797 and 2155639806.

It is not an unprimeable number, because it can be changed into a prime (2155639891) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2100501 + ... + 2101526.

It is an arithmetic number, because the mean of its divisors is an integer number (210101400).

Almost surely, 2^2155639851 is an apocalyptic number.

2155639851 is a deficient number, since it is larger than the sum of its proper divisors (1205982549).

2155639851 is a wasteful number, since it uses less digits than its factorization.

2155639851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4202055 (or 4202049 counting only the distinct ones).

The product of its digits is 324000, while the sum is 45.

The square root of 2155639851 is about 46428.8687241031. The cubic root of 2155639851 is about 1291.7904451306.

The spelling of 2155639851 in words is "two billion, one hundred fifty-five million, six hundred thirty-nine thousand, eight hundred fifty-one".