21530030455 has 16 divisors (see below), whose sum is σ = 26539227360. Its totient is φ = 16755403392.

The previous prime is 21530030437. The next prime is 21530030507. The reversal of 21530030455 is 55403003512.

It is a cyclic number.

It is not a de Polignac number, because 21530030455 - 2⁹ = 21530029943 is a prime.

It is a super-2 number, since 2×21530030455² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1981297 + ... + 1992133.

It is an arithmetic number, because the mean of its divisors is an integer number (1658701710).

Almost surely, 2^21530030455 is an apocalyptic number.

21530030455 is a deficient number, since it is larger than the sum of its proper divisors (5009196905).

21530030455 is a wasteful number, since it uses less digits than its factorization.

21530030455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21618.

The product of its (nonzero) digits is 9000, while the sum is 28.

Adding to 21530030455 its reverse (55403003512), we get a palindrome (76933033967).

The spelling of 21530030455 in words is "twenty-one billion, five hundred thirty million, thirty thousand, four hundred fifty-five".