21153515273 has 16 divisors (see below), whose sum is σ = 23706903744. Its totient is φ = 18705476160.

The previous prime is 21153515239. The next prime is 21153515281. The reversal of 21153515273 is 37251535112.

It is a cyclic number.

It is not a de Polignac number, because 21153515273 - 2⁶ = 21153515209 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21153515473) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2517986 + ... + 2526372.

It is an arithmetic number, because the mean of its divisors is an integer number (1481681484).

Almost surely, 2^21153515273 is an apocalyptic number.

It is an amenable number.

21153515273 is a deficient number, since it is larger than the sum of its proper divisors (2553388471).

21153515273 is a wasteful number, since it uses less digits than its factorization.

21153515273 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14632.

The product of its digits is 31500, while the sum is 35.

The spelling of 21153515273 in words is "twenty-one billion, one hundred fifty-three million, five hundred fifteen thousand, two hundred seventy-three".