15993481 has 8 divisors (see below), whose sum is σ = 19353600. Its totient is φ = 12902208.

The previous prime is 15993443. The next prime is 15993499. The reversal of 15993481 is 18439951.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 15993481 - 2¹⁷ = 15862409 is a prime.

It is a super-2 number, since 2×15993481² = 511582868994722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (15993401) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 67081 + ... + 67318.

It is an arithmetic number, because the mean of its divisors is an integer number (2419200).

Almost surely, 2^15993481 is an apocalyptic number.

It is an amenable number.

15993481 is a deficient number, since it is larger than the sum of its proper divisors (3360119).

15993481 is a wasteful number, since it uses less digits than its factorization.

15993481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134423.

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

The square root of 15993481 is about 3999.1850419804. The cubic root of 15993481 is about 251.9499827245.

The spelling of 15993481 in words is "fifteen million, nine hundred ninety-three thousand, four hundred eighty-one".