39977891 has 2 divisors, whose sum is σ = 39977892. Its totient is φ = 39977890.

The previous prime is 39977857. The next prime is 39977909. The reversal of 39977891 is 19877993.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 39977891 - 2¹⁸ = 39715747 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (39977851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19988945 + 19988946.

It is an arithmetic number, because the mean of its divisors is an integer number (19988946).

Almost surely, 2^39977891 is an apocalyptic number.

39977891 is a deficient number, since it is larger than the sum of its proper divisors (1).

39977891 is an equidigital number, since it uses as much as digits as its factorization.

39977891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 857304, while the sum is 53.

The square root of 39977891 is about 6322.8072088274. The cubic root of 39977891 is about 341.9321679591.

The spelling of 39977891 in words is "thirty-nine million, nine hundred seventy-seven thousand, eight hundred ninety-one".