21165503303 has 6 divisors (see below), whose sum is σ = 24621095736. Its totient is φ = 18141859932.

The previous prime is 21165503299. The next prime is 21165503327. The reversal of 21165503303 is 30330556112.

It is not a de Polignac number, because 21165503303 - 2² = 21165503299 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21165503383) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 215974475 + ... + 215974572.

It is an arithmetic number, because the mean of its divisors is an integer number (4103515956).

Almost surely, 2^21165503303 is an apocalyptic number.

21165503303 is a deficient number, since it is larger than the sum of its proper divisors (3455592433).

21165503303 is an equidigital number, since it uses as much as digits as its factorization.

21165503303 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 431949061 (or 431949054 counting only the distinct ones).

The product of its (nonzero) digits is 8100, while the sum is 29.

The spelling of 21165503303 in words is "twenty-one billion, one hundred sixty-five million, five hundred three thousand, three hundred three".