15551643 has 4 divisors (see below), whose sum is σ = 20735528. Its totient is φ = 10367760.

The previous prime is 15551639. The next prime is 15551659. The reversal of 15551643 is 34615551.

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

It is not a de Polignac number, because 15551643 - 2² = 15551639 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 15551643.

It is not an unprimeable number, because it can be changed into a prime (15551603) 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, 2591938 + ... + 2591943.

It is an arithmetic number, because the mean of its divisors is an integer number (5183882).

Almost surely, 2^15551643 is an apocalyptic number.

15551643 is a deficient number, since it is larger than the sum of its proper divisors (5183885).

15551643 is an equidigital number, since it uses as much as digits as its factorization.

15551643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5183884.

The product of its digits is 9000, while the sum is 30.

The square root of 15551643 is about 3943.5571505939. The cubic root of 15551643 is about 249.6081487981.

The spelling of 15551643 in words is "fifteen million, five hundred fifty-one thousand, six hundred forty-three".