405901591 has 2 divisors, whose sum is σ = 405901592. Its totient is φ = 405901590.

The previous prime is 405901583. The next prime is 405901621. The reversal of 405901591 is 195109504.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 405901591 - 2³ = 405901583 is a prime.

It is a super-2 number, since 2×405901591² = 329512203152662562, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (405901501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202950795 + 202950796.

It is an arithmetic number, because the mean of its divisors is an integer number (202950796).

Almost surely, 2^405901591 is an apocalyptic number.

405901591 is a deficient number, since it is larger than the sum of its proper divisors (1).

405901591 is an equidigital number, since it uses as much as digits as its factorization.

405901591 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8100, while the sum is 34.

The square root of 405901591 is about 20146.9995532834. Note that the first 3 decimals coincide. The cubic root of 405901591 is about 740.4122313580.

The spelling of 405901591 in words is "four hundred five million, nine hundred one thousand, five hundred ninety-one".