40721531 has 2 divisors, whose sum is σ = 40721532. Its totient is φ = 40721530.

The previous prime is 40721521. The next prime is 40721567. The reversal of 40721531 is 13512704.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 40721531 - 2¹⁰ = 40720507 is a prime.

It is a super-2 number, since 2×40721531² = 3316486173967922, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 40721497 and 40721506.

It is not a weakly prime, because it can be changed into another prime (40721501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20360765 + 20360766.

It is an arithmetic number, because the mean of its divisors is an integer number (20360766).

Almost surely, 2^40721531 is an apocalyptic number.

40721531 is a deficient number, since it is larger than the sum of its proper divisors (1).

40721531 is an equidigital number, since it uses as much as digits as its factorization.

40721531 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 40721531 is about 6381.3424136305. The cubic root of 40721531 is about 344.0392819528.

The spelling of 40721531 in words is "forty million, seven hundred twenty-one thousand, five hundred thirty-one".