2156209225 has 27 divisors (see below), whose sum is σ = 2758906101. Its totient is φ = 1671660000.

The previous prime is 2156209199. The next prime is 2156209241. The reversal of 2156209225 is 5229026512.

The square root of 2156209225 is 46435.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 204690249 + 1951518976 = 14307^2 + 44176^2 .

It is not a de Polignac number, because 2156209225 - 2⁵ = 2156209193 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 8590350 + ... + 8590600.

Almost surely, 2^2156209225 is an apocalyptic number.

2156209225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

2156209225 is the 46435-th square number.

2156209225 is the 23218-th centered octagonal number.

It is an amenable number.

2156209225 is a deficient number, since it is larger than the sum of its proper divisors (602696876).

2156209225 is an frugal number, since it uses more digits than its factorization.

2156209225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 586 (or 293 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 34.

The cubic root of 2156209225 is about 1291.9041696232.

The spelling of 2156209225 in words is "two billion, one hundred fifty-six million, two hundred nine thousand, two hundred twenty-five".