15421998 has 8 divisors (see below), whose sum is σ = 30844008. Its totient is φ = 5140664.

The previous prime is 15421979. The next prime is 15421999. The reversal of 15421998 is 89912451.

It is a sphenic number, since it is the product of 3 distinct primes.

15421998 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15421999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1285161 + ... + 1285172.

It is an arithmetic number, because the mean of its divisors is an integer number (3855501).

Almost surely, 2^15421998 is an apocalyptic number.

15421998 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

15421998 is a wasteful number, since it uses less digits than its factorization.

15421998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2570338.

The product of its digits is 25920, while the sum is 39.

The square root of 15421998 is about 3927.0851786026. The cubic root of 15421998 is about 248.9125997671.

The spelling of 15421998 in words is "fifteen million, four hundred twenty-one thousand, nine hundred ninety-eight".