15202420421 has 4 divisors (see below), whose sum is σ = 15203393100. Its totient is φ = 15201447744.

The previous prime is 15202420393. The next prime is 15202420433. The reversal of 15202420421 is 12402420251.

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

It can be written as a sum of positive squares in 2 ways, for example, as 7648377025 + 7554043396 = 87455^2 + 86914^2 .

It is a cyclic number.

It is not a de Polignac number, because 15202420421 - 2²⁶ = 15135311557 is a prime.

It is a super-2 number, since 2×15202420421² (a number of 21 digits) contains 22 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 (15202420721) 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, 462506 + ... + 494283.

It is an arithmetic number, because the mean of its divisors is an integer number (3800848275).

Almost surely, 2^15202420421 is an apocalyptic number.

It is an amenable number.

15202420421 is a deficient number, since it is larger than the sum of its proper divisors (972679).

15202420421 is an equidigital number, since it uses as much as digits as its factorization.

15202420421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 972678.

The product of its (nonzero) digits is 1280, while the sum is 23.

Adding to 15202420421 its reverse (12402420251), we get a palindrome (27604840672).

The spelling of 15202420421 in words is "fifteen billion, two hundred two million, four hundred twenty thousand, four hundred twenty-one".