2151555 has 32 divisors (see below), whose sum is σ = 4067328. Its totient is φ = 950400.

The previous prime is 2151533. The next prime is 2151563. The reversal of 2151555 is 5551512.

2151555 = T₈₃ + T₈₄ + ... + T₂₃₇.

It is not a de Polignac number, because 2151555 - 2¹⁰ = 2150531 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2925 + ... + 3585.

It is an arithmetic number, because the mean of its divisors is an integer number (127104).

2^2151555 is an apocalyptic number.

2151555 is a deficient number, since it is larger than the sum of its proper divisors (1915773).

2151555 is a wasteful number, since it uses less digits than its factorization.

2151555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 707.

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

The square root of 2151555 is about 1466.8179846184. The cubic root of 2151555 is about 129.0973965499.

It can be divided in two parts, 215 and 1555, that added together give a triangular number (1770 = T₅₉).

The spelling of 2151555 in words is "two million, one hundred fifty-one thousand, five hundred fifty-five".