2157181087 has 2 divisors, whose sum is σ = 2157181088. Its totient is φ = 2157181086.

The previous prime is 2157181079. The next prime is 2157181123. The reversal of 2157181087 is 7801817512.

2157181087 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2157181087 - 2³ = 2157181079 is a prime.

It is a super-2 number, since 2×2157181087² = 9306860484221003138, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2157181007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1078590543 + 1078590544.

It is an arithmetic number, because the mean of its divisors is an integer number (1078590544).

Almost surely, 2^2157181087 is an apocalyptic number.

2157181087 is a deficient number, since it is larger than the sum of its proper divisors (1).

2157181087 is an equidigital number, since it uses as much as digits as its factorization.

2157181087 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31360, while the sum is 40.

The square root of 2157181087 is about 46445.4635782656. The cubic root of 2157181087 is about 1292.0982392224.

Adding to 2157181087 its reverse (7801817512), we get a palindrome (9958998599).

The spelling of 2157181087 in words is "two billion, one hundred fifty-seven million, one hundred eighty-one thousand, eighty-seven".