21153665233 has 8 divisors (see below), whose sum is σ = 22435401600. Its totient is φ = 19876084800.

The previous prime is 21153665209. The next prime is 21153665243. The reversal of 21153665233 is 33256635112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21153665233 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21153665192 and 21153665201.

It is not an unprimeable number, because it can be changed into a prime (21153665243) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1028493 + ... + 1048858.

It is an arithmetic number, because the mean of its divisors is an integer number (2804425200).

Almost surely, 2^21153665233 is an apocalyptic number.

It is an amenable number.

21153665233 is a deficient number, since it is larger than the sum of its proper divisors (1281736367).

21153665233 is a wasteful number, since it uses less digits than its factorization.

21153665233 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2077967.

The product of its digits is 97200, while the sum is 37.

The spelling of 21153665233 in words is "twenty-one billion, one hundred fifty-three million, six hundred sixty-five thousand, two hundred thirty-three".