15900138 has 40 divisors (see below), whose sum is σ = 36234660. Its totient is φ = 5209920.

The previous prime is 15900133. The next prime is 15900167. The reversal of 15900138 is 83100951.

It can be written as a sum of positive squares in 2 ways, for example, as 15896169 + 3969 = 3987^2 + 63^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (15900133) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 9078 + ... + 10686.

Almost surely, 2^15900138 is an apocalyptic number.

15900138 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 15900138, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18117330).

15900138 is an abundant number, since it is smaller than the sum of its proper divisors (20334522).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

15900138 is a wasteful number, since it uses less digits than its factorization.

15900138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1684 (or 1675 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 27.

The square root of 15900138 is about 3987.4977115981. The cubic root of 15900138 is about 251.4588728669.

The spelling of 15900138 in words is "fifteen million, nine hundred thousand, one hundred thirty-eight".