187913681 has 2 divisors, whose sum is σ = 187913682. Its totient is φ = 187913680.

The previous prime is 187913653. The next prime is 187913717. The reversal of 187913681 is 186319781.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 108347281 + 79566400 = 10409^2 + 8920^2 .

It is a cyclic number.

It is not a de Polignac number, because 187913681 - 2¹⁰ = 187912657 is a prime.

It is a super-2 number, since 2×187913681² = 70623103013939522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (187913651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 93956840 + 93956841.

It is an arithmetic number, because the mean of its divisors is an integer number (93956841).

Almost surely, 2^187913681 is an apocalyptic number.

It is an amenable number.

187913681 is a deficient number, since it is larger than the sum of its proper divisors (1).

187913681 is an equidigital number, since it uses as much as digits as its factorization.

187913681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 72576, while the sum is 44.

The square root of 187913681 is about 13708.1611093538. The cubic root of 187913681 is about 572.7777423408. Note that the first 4 decimals are identical.

The spelling of 187913681 in words is "one hundred eighty-seven million, nine hundred thirteen thousand, six hundred eighty-one".