21051551433 has 8 divisors (see below), whose sum is σ = 30620438496. Its totient is φ = 12758516000.

The previous prime is 21051551387. The next prime is 21051551447. The reversal of 21051551433 is 33415515012.

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

It is a cyclic number.

It is not a de Polignac number, because 21051551433 - 2²⁶ = 20984442569 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21051551433.

It is not an unprimeable number, because it can be changed into a prime (21051551453) 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, 318962868 + ... + 318962933.

It is an arithmetic number, because the mean of its divisors is an integer number (3827554812).

Almost surely, 2^21051551433 is an apocalyptic number.

It is an amenable number.

21051551433 is a deficient number, since it is larger than the sum of its proper divisors (9568887063).

21051551433 is a wasteful number, since it uses less digits than its factorization.

21051551433 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 637925815.

The product of its (nonzero) digits is 9000, while the sum is 30.

The spelling of 21051551433 in words is "twenty-one billion, fifty-one million, five hundred fifty-one thousand, four hundred thirty-three".