2131710781 has 2 divisors, whose sum is σ = 2131710782. Its totient is φ = 2131710780.

The previous prime is 2131710727. The next prime is 2131710797. The reversal of 2131710781 is 1870171312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1781684100 + 350026681 = 42210^2 + 18709^2 .

It is a cyclic number.

It is not a de Polignac number, because 2131710781 - 2⁷ = 2131710653 is a prime.

It is a super-2 number, since 2×2131710781² = 9088381707663259922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2131710181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1065855390 + 1065855391.

It is an arithmetic number, because the mean of its divisors is an integer number (1065855391).

Almost surely, 2^2131710781 is an apocalyptic number.

It is an amenable number.

2131710781 is a deficient number, since it is larger than the sum of its proper divisors (1).

2131710781 is an equidigital number, since it uses as much as digits as its factorization.

2131710781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2352, while the sum is 31.

The square root of 2131710781 is about 46170.4535498624. The cubic root of 2131710781 is about 1286.9927306448.

The spelling of 2131710781 in words is "two billion, one hundred thirty-one million, seven hundred ten thousand, seven hundred eighty-one".