21403355265 has 24 divisors (see below), whose sum is σ = 38295898368. Its totient is φ = 11046892320.

The previous prime is 21403355227. The next prime is 21403355269. The reversal of 21403355265 is 56255330412.

21403355265 is a `hidden beast` number, since 2 + 1 + 40 + 3 + 3 + 552 + 65 = 666.

It is not a de Polignac number, because 21403355265 - 2¹³ = 21403347073 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21403355269) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7670059 + ... + 7672848.

It is an arithmetic number, because the mean of its divisors is an integer number (1595662432).

Almost surely, 2^21403355265 is an apocalyptic number.

It is an amenable number.

21403355265 is a deficient number, since it is larger than the sum of its proper divisors (16892543103).

21403355265 is a wasteful number, since it uses less digits than its factorization.

21403355265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15342949 (or 15342946 counting only the distinct ones).

The product of its (nonzero) digits is 108000, while the sum is 36.

Adding to 21403355265 its reverse (56255330412), we get a palindrome (77658685677).

The spelling of 21403355265 in words is "twenty-one billion, four hundred three million, three hundred fifty-five thousand, two hundred sixty-five".