39006779921 has 2 divisors, whose sum is σ = 39006779922. Its totient is φ = 39006779920.

The previous prime is 39006779879. The next prime is 39006779951. The reversal of 39006779921 is 12997760093.

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., 36435174400 + 2571605521 = 190880^2 + 50711^2 .

It is a cyclic number.

It is not a de Polignac number, because 39006779921 - 2³⁰ = 37933038097 is a prime.

It is not a weakly prime, because it can be changed into another prime (39006779951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19503389960 + 19503389961.

It is an arithmetic number, because the mean of its divisors is an integer number (19503389961).

Almost surely, 2^39006779921 is an apocalyptic number.

It is an amenable number.

39006779921 is a deficient number, since it is larger than the sum of its proper divisors (1).

39006779921 is an equidigital number, since it uses as much as digits as its factorization.

39006779921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1285956, while the sum is 53.

The spelling of 39006779921 in words is "thirty-nine billion, six million, seven hundred seventy-nine thousand, nine hundred twenty-one".