21004535051 has 4 divisors (see below), whose sum is σ = 21008425152. Its totient is φ = 21000644952.

The previous prime is 21004535029. The next prime is 21004535059. The reversal of 21004535051 is 15053540012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21004535051 - 2⁶ = 21004534987 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21004535051.

It is not an unprimeable number, because it can be changed into a prime (21004535059) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1936940 + ... + 1947753.

It is an arithmetic number, because the mean of its divisors is an integer number (5252106288).

Almost surely, 2^21004535051 is an apocalyptic number.

21004535051 is a deficient number, since it is larger than the sum of its proper divisors (3890101).

21004535051 is an equidigital number, since it uses as much as digits as its factorization.

21004535051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3890100.

The product of its (nonzero) digits is 3000, while the sum is 26.

The spelling of 21004535051 in words is "twenty-one billion, four million, five hundred thirty-five thousand, fifty-one".