21820199519 has 2 divisors, whose sum is σ = 21820199520. Its totient is φ = 21820199518.

The previous prime is 21820199441. The next prime is 21820199537. The reversal of 21820199519 is 91599102812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21820199519 - 2⁸ = 21820199263 is a prime.

It is a super-2 number, since 2×21820199519² (a number of 21 digits) contains 22 as substring.

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 (21820199419) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10910099759 + 10910099760.

It is an arithmetic number, because the mean of its divisors is an integer number (10910099760).

Almost surely, 2^21820199519 is an apocalyptic number.

21820199519 is a deficient number, since it is larger than the sum of its proper divisors (1).

21820199519 is an equidigital number, since it uses as much as digits as its factorization.

21820199519 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 116640, while the sum is 47.

The spelling of 21820199519 in words is "twenty-one billion, eight hundred twenty million, one hundred ninety-nine thousand, five hundred nineteen".