40156021 has 2 divisors, whose sum is σ = 40156022. Its totient is φ = 40156020.

The previous prime is 40156013. The next prime is 40156069. The reversal of 40156021 is 12065104.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 35533521 + 4622500 = 5961^2 + 2150^2 .

It is a cyclic number.

It is not a de Polignac number, because 40156021 - 2³ = 40156013 is a prime.

It is a super-2 number, since 2×40156021² = 3225012045104882, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 40156021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40156121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20078010 + 20078011.

It is an arithmetic number, because the mean of its divisors is an integer number (20078011).

Almost surely, 2^40156021 is an apocalyptic number.

It is an amenable number.

40156021 is a deficient number, since it is larger than the sum of its proper divisors (1).

40156021 is an equidigital number, since it uses as much as digits as its factorization.

40156021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 40156021 is about 6336.8778590091. The cubic root of 40156021 is about 342.4392660527.

The spelling of 40156021 in words is "forty million, one hundred fifty-six thousand, twenty-one".