21990043453 has 12 divisors (see below), whose sum is σ = 25609944960. Its totient is φ = 18826731672.

The previous prime is 21990043451. The next prime is 21990043483. The reversal of 21990043453 is 35434009912.

It is not a de Polignac number, because 21990043453 - 2¹ = 21990043451 is a prime.

It is a super-2 number, since 2×21990043453² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21990043451) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 217723 + ... + 302296.

It is an arithmetic number, because the mean of its divisors is an integer number (2134162080).

Almost surely, 2^21990043453 is an apocalyptic number.

It is an amenable number.

21990043453 is a deficient number, since it is larger than the sum of its proper divisors (3619901507).

21990043453 is an equidigital number, since it uses as much as digits as its factorization.

21990043453 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 520896 (or 520889 counting only the distinct ones).

The product of its (nonzero) digits is 116640, while the sum is 40.

The spelling of 21990043453 in words is "twenty-one billion, nine hundred ninety million, forty-three thousand, four hundred fifty-three".