15320981 has 4 divisors (see below), whose sum is σ = 16499532. Its totient is φ = 14142432.

The previous prime is 15320971. The next prime is 15320983. The reversal of 15320981 is 18902351.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9821956 + 5499025 = 3134^2 + 2345^2 .

It is a cyclic number.

It is not a de Polignac number, because 15320981 - 2⁶ = 15320917 is a prime.

It is a super-2 number, since 2×15320981² = 469464917604722, 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 (15320983) 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, 589256 + ... + 589281.

It is an arithmetic number, because the mean of its divisors is an integer number (4124883).

Almost surely, 2^15320981 is an apocalyptic number.

It is an amenable number.

15320981 is a deficient number, since it is larger than the sum of its proper divisors (1178551).

15320981 is a wasteful number, since it uses less digits than its factorization.

15320981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1178550.

The product of its (nonzero) digits is 2160, while the sum is 29.

The square root of 15320981 is about 3914.2024730461. The cubic root of 15320981 is about 248.3679339604.

The spelling of 15320981 in words is "fifteen million, three hundred twenty thousand, nine hundred eighty-one".