40355921 has 2 divisors, whose sum is σ = 40355922. Its totient is φ = 40355920.

The previous prime is 40355911. The next prime is 40355923. The reversal of 40355921 is 12955304.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21520321 + 18835600 = 4639^2 + 4340^2 .

It is a cyclic number.

It is not a de Polignac number, because 40355921 - 2⁶ = 40355857 is a prime.

Together with 40355923, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (40355923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20177960 + 20177961.

It is an arithmetic number, because the mean of its divisors is an integer number (20177961).

Almost surely, 2^40355921 is an apocalyptic number.

It is an amenable number.

40355921 is a deficient number, since it is larger than the sum of its proper divisors (1).

40355921 is an equidigital number, since it uses as much as digits as its factorization.

40355921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5400, while the sum is 29.

The square root of 40355921 is about 6352.6310297388. The cubic root of 40355921 is about 343.0065560998.

The spelling of 40355921 in words is "forty million, three hundred fifty-five thousand, nine hundred twenty-one".