15535042421 has 4 divisors (see below), whose sum is σ = 16210479072. Its totient is φ = 14859605772.

The previous prime is 15535042417. The next prime is 15535042423. The reversal of 15535042421 is 12424053551.

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.

It is a cyclic number.

It is not a de Polignac number, because 15535042421 - 2² = 15535042417 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 (15535042423) 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, 337718291 + ... + 337718336.

It is an arithmetic number, because the mean of its divisors is an integer number (4052619768).

Almost surely, 2^15535042421 is an apocalyptic number.

It is an amenable number.

15535042421 is a deficient number, since it is larger than the sum of its proper divisors (675436651).

15535042421 is an equidigital number, since it uses as much as digits as its factorization.

15535042421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 675436650.

The product of its (nonzero) digits is 24000, while the sum is 32.

Adding to 15535042421 its reverse (12424053551), we get a palindrome (27959095972).

The spelling of 15535042421 in words is "fifteen billion, five hundred thirty-five million, forty-two thousand, four hundred twenty-one".