2155401 has 6 divisors (see below), whose sum is σ = 3113370. Its totient is φ = 1436928.

The previous prime is 2155397. The next prime is 2155409. The reversal of 2155401 is 1045512.

It can be written as a sum of positive squares in only one way, i.e., 1904400 + 251001 = 1380^2 + 501^2 .

It is not a de Polignac number, because 2155401 - 2² = 2155397 is a prime.

It is a zygodrome in base 3.

It is not an unprimeable number, because it can be changed into a prime (2155409) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 119736 + ... + 119753.

It is an arithmetic number, because the mean of its divisors is an integer number (518895).

2^2155401 is an apocalyptic number.

It is an amenable number.

2155401 is a deficient number, since it is larger than the sum of its proper divisors (957969).

2155401 is a wasteful number, since it uses less digits than its factorization.

2155401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 239495 (or 239492 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

The square root of 2155401 is about 1468.1284003792. The cubic root of 2155401 is about 129.1742732022.

It can be divided in two parts, 2155 and 401, that added together give a triangular number (2556 = T₇₁).

The spelling of 2155401 in words is "two million, one hundred fifty-five thousand, four hundred one".