21551501242023 has 4 divisors (see below), whose sum is σ = 28735334989368. Its totient is φ = 14367667494680.

The previous prime is 21551501241997. The next prime is 21551501242049. The reversal of 21551501242023 is 32024210515512.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21551501241997) and next prime (21551501242049).

It is a cyclic number.

It is not a de Polignac number, because 21551501242023 - 2¹⁶ = 21551501176487 is a prime.

It is a super-2 number, since 2×21551501242023² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21551501242123) 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, 3591916873668 + ... + 3591916873673.

It is an arithmetic number, because the mean of its divisors is an integer number (7183833747342).

Almost surely, 2^{21551501242023} is an apocalyptic number.

21551501242023 is a deficient number, since it is larger than the sum of its proper divisors (7183833747345).

21551501242023 is an equidigital number, since it uses as much as digits as its factorization.

21551501242023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7183833747344.

The product of its (nonzero) digits is 24000, while the sum is 33.

Adding to 21551501242023 its reverse (32024210515512), we get a palindrome (53575711757535).

The spelling of 21551501242023 in words is "twenty-one trillion, five hundred fifty-one billion, five hundred one million, two hundred forty-two thousand, twenty-three".