2155551 has 8 divisors (see below), whose sum is σ = 2885424. Its totient is φ = 1431360.

The previous prime is 2155519. The next prime is 2155579. The reversal of 2155551 is 1555512.

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

It is not a de Polignac number, because 2155551 - 2⁵ = 2155519 is a prime.

It is a super-2 number, since 2×2155551² = 9292800227202, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2155511) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 436 + ... + 2121.

It is an arithmetic number, because the mean of its divisors is an integer number (360678).

2^2155551 is an apocalyptic number.

2155551 is a deficient number, since it is larger than the sum of its proper divisors (729873).

2155551 is a wasteful number, since it uses less digits than its factorization.

2155551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2841.

The product of its digits is 1250, while the sum is 24.

The square root of 2155551 is about 1468.1794849404. The cubic root of 2155551 is about 129.1772696580.

The spelling of 2155551 in words is "two million, one hundred fifty-five thousand, five hundred fifty-one".