15993945 has 48 divisors (see below), whose sum is σ = 30700800. Its totient is φ = 7637760.

The previous prime is 15993941. The next prime is 15993949. The reversal of 15993945 is 54939951.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (15993941) and next prime (15993949).

It is not a de Polignac number, because 15993945 - 2² = 15993941 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 15993945.

It is not an unprimeable number, because it can be changed into a prime (15993941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 38901 + ... + 39309.

It is an arithmetic number, because the mean of its divisors is an integer number (639600).

Almost surely, 2^15993945 is an apocalyptic number.

15993945 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

15993945 is a deficient number, since it is larger than the sum of its proper divisors (14706855).

15993945 is a wasteful number, since it uses less digits than its factorization.

15993945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 510 (or 507 counting only the distinct ones).

The product of its digits is 218700, while the sum is 45.

The square root of 15993945 is about 3999.2430533790. The cubic root of 15993945 is about 251.9524192102.

The spelling of 15993945 in words is "fifteen million, nine hundred ninety-three thousand, nine hundred forty-five".