15420399 has 4 divisors (see below), whose sum is σ = 20560536. Its totient is φ = 10280264.

The previous prime is 15420367. The next prime is 15420401. The reversal of 15420399 is 99302451.

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

It is a cyclic number.

It is not a de Polignac number, because 15420399 - 2⁵ = 15420367 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15420329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2570064 + ... + 2570069.

It is an arithmetic number, because the mean of its divisors is an integer number (5140134).

Almost surely, 2^15420399 is an apocalyptic number.

15420399 is a deficient number, since it is larger than the sum of its proper divisors (5140137).

15420399 is an equidigital number, since it uses as much as digits as its factorization.

15420399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5140136.

The product of its (nonzero) digits is 9720, while the sum is 33.

The square root of 15420399 is about 3926.8815872140. The cubic root of 15420399 is about 248.9039967961.

The spelling of 15420399 in words is "fifteen million, four hundred twenty thousand, three hundred ninety-nine".