40396921 has 2 divisors, whose sum is σ = 40396922. Its totient is φ = 40396920.

The previous prime is 40396903. The next prime is 40396927. The reversal of 40396921 is 12969304.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 26409321 + 13987600 = 5139^2 + 3740^2 .

It is a cyclic number.

It is not a de Polignac number, because 40396921 - 2¹³ = 40388729 is a prime.

It is a super-2 number, since 2×40396921² = 3263822452560482, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (40396927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20198460 + 20198461.

It is an arithmetic number, because the mean of its divisors is an integer number (20198461).

Almost surely, 2^40396921 is an apocalyptic number.

It is an amenable number.

40396921 is a deficient number, since it is larger than the sum of its proper divisors (1).

40396921 is an equidigital number, since it uses as much as digits as its factorization.

40396921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11664, while the sum is 34.

The square root of 40396921 is about 6355.8572199193. The cubic root of 40396921 is about 343.1226770933.

The spelling of 40396921 in words is "forty million, three hundred ninety-six thousand, nine hundred twenty-one".