21455155234531 has 4 divisors (see below), whose sum is σ = 21547237446072. Its totient is φ = 21363073022992.

The previous prime is 21455155234523. The next prime is 21455155234543. The reversal of 21455155234531 is 13543255155412.

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 21455155234531 - 2³ = 21455155234523 is a prime.

It is a super-2 number, since 2×21455155234531² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21455155237531) 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, 46041105421 + ... + 46041105886.

It is an arithmetic number, because the mean of its divisors is an integer number (5386809361518).

Almost surely, 2^{21455155234531} is an apocalyptic number.

21455155234531 is a deficient number, since it is larger than the sum of its proper divisors (92082211541).

21455155234531 is an equidigital number, since it uses as much as digits as its factorization.

21455155234531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92082211540.

The product of its digits is 1800000, while the sum is 46.

The spelling of 21455155234531 in words is "twenty-one trillion, four hundred fifty-five billion, one hundred fifty-five million, two hundred thirty-four thousand, five hundred thirty-one".