39621979 has 2 divisors, whose sum is σ = 39621980. Its totient is φ = 39621978.

The previous prime is 39621941. The next prime is 39622003. The reversal of 39621979 is 97912693.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 39621979 - 2⁷ = 39621851 is a prime.

It is not a weakly prime, because it can be changed into another prime (39621929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19810989 + 19810990.

It is an arithmetic number, because the mean of its divisors is an integer number (19810990).

Almost surely, 2^39621979 is an apocalyptic number.

39621979 is a deficient number, since it is larger than the sum of its proper divisors (1).

39621979 is an equidigital number, since it uses as much as digits as its factorization.

39621979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 183708, while the sum is 46.

The square root of 39621979 is about 6294.5991929590. The cubic root of 39621979 is about 340.9144328838.

The spelling of 39621979 in words is "thirty-nine million, six hundred twenty-one thousand, nine hundred seventy-nine".