40069921 has 2 divisors, whose sum is σ = 40069922. Its totient is φ = 40069920.

The previous prime is 40069889. The next prime is 40069943. The reversal of 40069921 is 12996004.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39551521 + 518400 = 6289^2 + 720^2 .

It is a cyclic number.

It is not a de Polignac number, because 40069921 - 2⁵ = 40069889 is a prime.

It is not a weakly prime, because it can be changed into another prime (40069951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20034960 + 20034961.

It is an arithmetic number, because the mean of its divisors is an integer number (20034961).

Almost surely, 2^40069921 is an apocalyptic number.

It is an amenable number.

40069921 is a deficient number, since it is larger than the sum of its proper divisors (1).

40069921 is an equidigital number, since it uses as much as digits as its factorization.

40069921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 40069921 is about 6330.0806471956. The cubic root of 40069921 is about 342.1943453841.

The spelling of 40069921 in words is "forty million, sixty-nine thousand, nine hundred twenty-one".