2156247 has 8 divisors (see below), whose sum is σ = 3194480. Its totient is φ = 1437480.

The previous prime is 2156221. The next prime is 2156251. The reversal of 2156247 is 7426512.

It is not a de Polignac number, because 2156247 - 2⁶ = 2156183 is a prime.

It is a super-2 number, since 2×2156247² = 9298802250018, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 79861 = 2156247 / (2 + 1 + 5 + 6 + 2 + 4 + 7).

It is an Ulam number.

It is a Duffinian number.

It is a zygodrome in base 3.

It is a self number, because there is not a number n which added to its sum of digits gives 2156247.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2156207) 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, 39904 + ... + 39957.

It is an arithmetic number, because the mean of its divisors is an integer number (399310).

2^2156247 is an apocalyptic number.

2156247 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

2156247 is a deficient number, since it is larger than the sum of its proper divisors (1038233).

2156247 is an equidigital number, since it uses as much as digits as its factorization.

2156247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79870 (or 79864 counting only the distinct ones).

The product of its digits is 3360, while the sum is 27.

The square root of 2156247 is about 1468.4164940506. The cubic root of 2156247 is about 129.1911713943.

It can be divided in two parts, 21562 and 47, that added together give a square (21609 = 147²).

The spelling of 2156247 in words is "two million, one hundred fifty-six thousand, two hundred forty-seven".