21753002621 has 24 divisors (see below), whose sum is σ = 25859730816. Its totient is φ = 18236843520.

The previous prime is 21753002597. The next prime is 21753002639. The reversal of 21753002621 is 12620035712.

It is a happy number.

It is not a de Polignac number, because 21753002621 - 2¹⁴ = 21752986237 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 (21753002641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6932765 + ... + 6935901.

It is an arithmetic number, because the mean of its divisors is an integer number (1077488784).

Almost surely, 2^21753002621 is an apocalyptic number.

It is an amenable number.

21753002621 is a deficient number, since it is larger than the sum of its proper divisors (4106728195).

21753002621 is a wasteful number, since it uses less digits than its factorization.

21753002621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6209 (or 6202 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 29.

The spelling of 21753002621 in words is "twenty-one billion, seven hundred fifty-three million, two thousand, six hundred twenty-one".