21515121502023 has 8 divisors (see below), whose sum is σ = 28694716181488. Its totient is φ = 14339470578624.

The previous prime is 21515121501989. The next prime is 21515121502033. The reversal of 21515121502023 is 32020512151512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21515121502023 - 2²¹ = 21515119404871 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21515121502033) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 985926286 + ... + 985948107.

It is an arithmetic number, because the mean of its divisors is an integer number (3586839522686).

Almost surely, 2^{21515121502023} is an apocalyptic number.

21515121502023 is a deficient number, since it is larger than the sum of its proper divisors (7179594679465).

21515121502023 is a wasteful number, since it uses less digits than its factorization.

21515121502023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1971878033.

The product of its (nonzero) digits is 6000, while the sum is 30.

Adding to 21515121502023 its reverse (32020512151512), we get a palindrome (53535633653535).

The spelling of 21515121502023 in words is "twenty-one trillion, five hundred fifteen billion, one hundred twenty-one million, five hundred two thousand, twenty-three".