15538942481 has 4 divisors (see below), whose sum is σ = 15539270964. Its totient is φ = 15538614000.

The previous prime is 15538942453. The next prime is 15538942493. The reversal of 15538942481 is 18424983551.

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 7745584081 + 7793358400 = 88009^2 + 88280^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15538942481 is a prime.

It is a super-2 number, since 2×15538942481² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15538942681) 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, 78290 + ... + 192891.

It is an arithmetic number, because the mean of its divisors is an integer number (3884817741).

Almost surely, 2^15538942481 is an apocalyptic number.

It is an amenable number.

15538942481 is a deficient number, since it is larger than the sum of its proper divisors (328483).

15538942481 is an equidigital number, since it uses as much as digits as its factorization.

15538942481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 328482.

The product of its digits is 1382400, while the sum is 50.

The spelling of 15538942481 in words is "fifteen billion, five hundred thirty-eight million, nine hundred forty-two thousand, four hundred eighty-one".