406213891 has 2 divisors, whose sum is σ = 406213892. Its totient is φ = 406213890.

The previous prime is 406213867. The next prime is 406213909. The reversal of 406213891 is 198312604.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 406213891 - 2⁵ = 406213859 is a prime.

It is not a weakly prime, because it can be changed into another prime (406213811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 203106945 + 203106946.

It is an arithmetic number, because the mean of its divisors is an integer number (203106946).

Almost surely, 2^406213891 is an apocalyptic number.

406213891 is a deficient number, since it is larger than the sum of its proper divisors (1).

406213891 is an equidigital number, since it uses as much as digits as its factorization.

406213891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 406213891 is about 20154.7485967948. The cubic root of 406213891 is about 740.6020733193.

The spelling of 406213891 in words is "four hundred six million, two hundred thirteen thousand, eight hundred ninety-one".