15728993281 has 4 divisors (see below), whose sum is σ = 15849062064. Its totient is φ = 15608924500.

The previous prime is 15728993243. The next prime is 15728993321. The reversal of 15728993281 is 18239982751.

It is a happy number.

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: 18239982751 = 1637 ⋅11142323.

It is a cyclic number.

It is not a de Polignac number, because 15728993281 - 2¹¹ = 15728991233 is a prime.

It is a super-2 number, since 2×15728993281² (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 (15728993201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 60034195 + ... + 60034456.

It is an arithmetic number, because the mean of its divisors is an integer number (3962265516).

Almost surely, 2^15728993281 is an apocalyptic number.

It is an amenable number.

15728993281 is a deficient number, since it is larger than the sum of its proper divisors (120068783).

15728993281 is a wasteful number, since it uses less digits than its factorization.

15728993281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120068782.

The product of its digits is 2177280, while the sum is 55.

The spelling of 15728993281 in words is "fifteen billion, seven hundred twenty-eight million, nine hundred ninety-three thousand, two hundred eighty-one".