15221380 has 12 divisors (see below), whose sum is σ = 31964940. Its totient is φ = 6088544.

The previous prime is 15221357. The next prime is 15221383. The reversal of 15221380 is 8312251.

It can be written as a sum of positive squares in 2 ways, for example, as 1855044 + 13366336 = 1362^2 + 3656^2 .

It is not an unprimeable number, because it can be changed into a prime (15221383) 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, 380515 + ... + 380554.

It is an arithmetic number, because the mean of its divisors is an integer number (2663745).

Almost surely, 2^15221380 is an apocalyptic number.

15221380 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

15221380 is an abundant number, since it is smaller than the sum of its proper divisors (16743560).

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

15221380 is a wasteful number, since it uses less digits than its factorization.

15221380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 761078 (or 761076 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 15221380 is about 3901.4587015628. The cubic root of 15221380 is about 247.8285538939.

The spelling of 15221380 in words is "fifteen million, two hundred twenty-one thousand, three hundred eighty".