19990879 has 2 divisors, whose sum is σ = 19990880. Its totient is φ = 19990878.

The previous prime is 19990849. The next prime is 19990891. The reversal of 19990879 is 97809991.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 19990879 - 2¹³ = 19982687 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19990849) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9995439 + 9995440.

It is an arithmetic number, because the mean of its divisors is an integer number (9995440).

Almost surely, 2^19990879 is an apocalyptic number.

19990879 is a deficient number, since it is larger than the sum of its proper divisors (1).

19990879 is an equidigital number, since it uses as much as digits as its factorization.

19990879 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 367416, while the sum is 52.

The square root of 19990879 is about 4471.1160799067. The cubic root of 19990879 is about 271.4004917133.

The spelling of 19990879 in words is "nineteen million, nine hundred ninety thousand, eight hundred seventy-nine".