15493981 has 4 divisors (see below), whose sum is σ = 15644512. Its totient is φ = 15343452.

The previous prime is 15493963. The next prime is 15493997. The reversal of 15493981 is 18939451.

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: 18939451 = 457 ⋅41443.

It is a cyclic number.

It is not a de Polignac number, because 15493981 - 2⁹ = 15493469 is a prime.

It is a super-2 number, since 2×15493981² = 480126894456722, which 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 (15493901) 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, 75111 + ... + 75316.

It is an arithmetic number, because the mean of its divisors is an integer number (3911128).

Almost surely, 2^15493981 is an apocalyptic number.

It is an amenable number.

15493981 is a deficient number, since it is larger than the sum of its proper divisors (150531).

15493981 is a wasteful number, since it uses less digits than its factorization.

15493981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150530.

The product of its digits is 38880, while the sum is 40.

The square root of 15493981 is about 3936.2394490173. The cubic root of 15493981 is about 249.2992697435.

The spelling of 15493981 in words is "fifteen million, four hundred ninety-three thousand, nine hundred eighty-one".