15502240021 has 4 divisors (see below), whose sum is σ = 15597345952. Its totient is φ = 15407134092.

The previous prime is 15502240009. The next prime is 15502240067. The reversal of 15502240021 is 12004220551.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12004220551 = 31 ⋅387232921.

It is a cyclic number.

It is not a de Polignac number, because 15502240021 - 2⁵ = 15502239989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 15502239974 and 15502240001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15502240001) 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, 47552721 + ... + 47553046.

It is an arithmetic number, because the mean of its divisors is an integer number (3899336488).

Almost surely, 2^15502240021 is an apocalyptic number.

It is an amenable number.

15502240021 is a deficient number, since it is larger than the sum of its proper divisors (95105931).

15502240021 is an equidigital number, since it uses as much as digits as its factorization.

15502240021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95105930.

The product of its (nonzero) digits is 800, while the sum is 22.

Adding to 15502240021 its reverse (12004220551), we get a palindrome (27506460572).

The spelling of 15502240021 in words is "fifteen billion, five hundred two million, two hundred forty thousand, twenty-one".