21123401504 has 24 divisors (see below), whose sum is σ = 41990457600. Its totient is φ = 10459158336.

The previous prime is 21123401471. The next prime is 21123401543. The reversal of 21123401504 is 40510432112.

It is a self number, because there is not a number n which added to its sum of digits gives 21123401504.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3201104 + ... + 3207695.

It is an arithmetic number, because the mean of its divisors is an integer number (1749602400).

Almost surely, 2^21123401504 is an apocalyptic number.

It is an amenable number.

21123401504 is a deficient number, since it is larger than the sum of its proper divisors (20867056096).

21123401504 is a wasteful number, since it uses less digits than its factorization.

21123401504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6408912 (or 6408904 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 23.

Adding to 21123401504 its reverse (40510432112), we get a palindrome (61633833616).

The spelling of 21123401504 in words is "twenty-one billion, one hundred twenty-three million, four hundred one thousand, five hundred four".