405689936891 has 2 divisors, whose sum is σ = 405689936892. Its totient is φ = 405689936890.

The previous prime is 405689936887. The next prime is 405689936923. The reversal of 405689936891 is 198639986504.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 405689936891 - 2² = 405689936887 is a prime.

It is not a weakly prime, because it can be changed into another prime (405689936831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202844968445 + 202844968446.

It is an arithmetic number, because the mean of its divisors is an integer number (202844968446).

Almost surely, 2^405689936891 is an apocalyptic number.

405689936891 is a deficient number, since it is larger than the sum of its proper divisors (1).

405689936891 is an equidigital number, since it uses as much as digits as its factorization.

405689936891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 100776960, while the sum is 68.

The spelling of 405689936891 in words is "four hundred five billion, six hundred eighty-nine million, nine hundred thirty-six thousand, eight hundred ninety-one".