40561999 has 2 divisors, whose sum is σ = 40562000. Its totient is φ = 40561998.

The previous prime is 40561993. The next prime is 40562003. The reversal of 40561999 is 99916504.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 40561999 - 2³ = 40561991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40561991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20280999 + 20281000.

It is an arithmetic number, because the mean of its divisors is an integer number (20281000).

Almost surely, 2^40561999 is an apocalyptic number.

40561999 is a deficient number, since it is larger than the sum of its proper divisors (1).

40561999 is an equidigital number, since it uses as much as digits as its factorization.

40561999 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 87480, while the sum is 43.

The square root of 40561999 is about 6368.8302693666. The cubic root of 40561999 is about 343.5894208004.

The spelling of 40561999 in words is "forty million, five hundred sixty-one thousand, nine hundred ninety-nine".