2131209081 has 12 divisors (see below), whose sum is σ = 3240435120. Its totient is φ = 1346026680.

The previous prime is 2131209079. The next prime is 2131209103. The reversal of 2131209081 is 1809021312.

It is not a de Polignac number, because 2131209081 - 2¹ = 2131209079 is a prime.

It is a super-2 number, since 2×2131209081² = 9084104293873729122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2131209061) 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, 6231435 + ... + 6231776.

It is an arithmetic number, because the mean of its divisors is an integer number (270036260).

Almost surely, 2^2131209081 is an apocalyptic number.

It is an amenable number.

2131209081 is a deficient number, since it is larger than the sum of its proper divisors (1109226039).

2131209081 is a wasteful number, since it uses less digits than its factorization.

2131209081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12463236 (or 12463233 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 2131209081 is about 46165.0201018044. The cubic root of 2131209081 is about 1286.8917577674.

The spelling of 2131209081 in words is "two billion, one hundred thirty-one million, two hundred nine thousand, eighty-one".