687922091 has 2 divisors, whose sum is σ = 687922092. Its totient is φ = 687922090.

The previous prime is 687922087. The next prime is 687922099. The reversal of 687922091 is 190229786.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 687922091 - 2² = 687922087 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (687922099) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343961045 + 343961046.

It is an arithmetic number, because the mean of its divisors is an integer number (343961046).

Almost surely, 2^687922091 is an apocalyptic number.

687922091 is a deficient number, since it is larger than the sum of its proper divisors (1).

687922091 is an equidigital number, since it uses as much as digits as its factorization.

687922091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108864, while the sum is 44.

The square root of 687922091 is about 26228.2689287723. The cubic root of 687922091 is about 882.7676684871.

The spelling of 687922091 in words is "six hundred eighty-seven million, nine hundred twenty-two thousand, ninety-one".