21499895623 has 2 divisors, whose sum is σ = 21499895624. Its totient is φ = 21499895622.

The previous prime is 21499895617. The next prime is 21499895663. The reversal of 21499895623 is 32659899412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21499895623 - 2⁵ = 21499895591 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21499895663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10749947811 + 10749947812.

It is an arithmetic number, because the mean of its divisors is an integer number (10749947812).

Almost surely, 2^21499895623 is an apocalyptic number.

21499895623 is a deficient number, since it is larger than the sum of its proper divisors (1).

21499895623 is an equidigital number, since it uses as much as digits as its factorization.

21499895623 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8398080, while the sum is 58.

The spelling of 21499895623 in words is "twenty-one billion, four hundred ninety-nine million, eight hundred ninety-five thousand, six hundred twenty-three".