21404525505 has 48 divisors (see below), whose sum is σ = 37717310400. Its totient is φ = 10357649280.

The previous prime is 21404525479. The next prime is 21404525531. The reversal of 21404525505 is 50552540412.

It is an interprime number because it is at equal distance from previous prime (21404525479) and next prime (21404525531).

It is not a de Polignac number, because 21404525505 - 2⁵ = 21404525473 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 937971 + ... + 960519.

It is an arithmetic number, because the mean of its divisors is an integer number (785777300).

Almost surely, 2^21404525505 is an apocalyptic number.

It is an amenable number.

21404525505 is a deficient number, since it is larger than the sum of its proper divisors (16312784895).

21404525505 is a wasteful number, since it uses less digits than its factorization.

21404525505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23102 (or 23091 counting only the distinct ones).

The product of its (nonzero) digits is 40000, while the sum is 33.

The spelling of 21404525505 in words is "twenty-one billion, four hundred four million, five hundred twenty-five thousand, five hundred five".