19640879 has 2 divisors, whose sum is σ = 19640880. Its totient is φ = 19640878.

The previous prime is 19640867. The next prime is 19640893. The reversal of 19640879 is 97804691.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19640879 - 2¹² = 19636783 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19640479) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9820439 + 9820440.

It is an arithmetic number, because the mean of its divisors is an integer number (9820440).

Almost surely, 2^19640879 is an apocalyptic number.

19640879 is a deficient number, since it is larger than the sum of its proper divisors (1).

19640879 is an equidigital number, since it uses as much as digits as its factorization.

19640879 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108864, while the sum is 44.

The square root of 19640879 is about 4431.8031319092. The cubic root of 19640879 is about 269.8072652874.

The spelling of 19640879 in words is "nineteen million, six hundred forty thousand, eight hundred seventy-nine".