15551990 has 8 divisors (see below), whose sum is σ = 27993600. Its totient is φ = 6220792.

The previous prime is 15551989. The next prime is 15551999. The reversal of 15551990 is 9915551.

It is a happy number.

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

It is a self number, because there is not a number n which added to its sum of digits gives 15551990.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15551999) 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, 777590 + ... + 777609.

It is an arithmetic number, because the mean of its divisors is an integer number (3499200).

Almost surely, 2^15551990 is an apocalyptic number.

15551990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

15551990 is a deficient number, since it is larger than the sum of its proper divisors (12441610).

15551990 is a wasteful number, since it uses less digits than its factorization.

15551990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1555206.

The product of its (nonzero) digits is 10125, while the sum is 35.

The square root of 15551990 is about 3943.6011461607. The cubic root of 15551990 is about 249.6100052661.

The spelling of 15551990 in words is "fifteen million, five hundred fifty-one thousand, nine hundred ninety".