21530400041023 has 4 divisors (see below), whose sum is σ = 21687556245840. Its totient is φ = 21373243836208.

The previous prime is 21530400040991. The next prime is 21530400041047. The reversal of 21530400041023 is 32014000403512.

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 21530400041023 - 2⁵ = 21530400040991 is a prime.

It is a super-4 number, since 4×21530400041023⁴ (a number of 54 digits) contains 4444 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 (21530400041063) 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, 78578102203 + ... + 78578102476.

It is an arithmetic number, because the mean of its divisors is an integer number (5421889061460).

Almost surely, 2^{21530400041023} is an apocalyptic number.

21530400041023 is a deficient number, since it is larger than the sum of its proper divisors (157156204817).

21530400041023 is a wasteful number, since it uses less digits than its factorization.

21530400041023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157156204816.

The product of its (nonzero) digits is 2880, while the sum is 25.

Adding to 21530400041023 its reverse (32014000403512), we get a palindrome (53544400444535).

The spelling of 21530400041023 in words is "twenty-one trillion, five hundred thirty billion, four hundred million, forty-one thousand, twenty-three".