19872551 has 2 divisors, whose sum is σ = 19872552. Its totient is φ = 19872550.

The previous prime is 19872497. The next prime is 19872563. The reversal of 19872551 is 15527891.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19872551 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19872451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9936275 + 9936276.

It is an arithmetic number, because the mean of its divisors is an integer number (9936276).

Almost surely, 2^19872551 is an apocalyptic number.

19872551 is a deficient number, since it is larger than the sum of its proper divisors (1).

19872551 is an equidigital number, since it uses as much as digits as its factorization.

19872551 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25200, while the sum is 38.

The square root of 19872551 is about 4457.8639503691. The cubic root of 19872551 is about 270.8639495382.

The spelling of 19872551 in words is "nineteen million, eight hundred seventy-two thousand, five hundred fifty-one".