1890721251225 has 135 divisors (see below), whose sum is σ = 3539911349793. Its totient is φ = 964680554880.

The previous prime is 1890721251203. The next prime is 1890721251233. The reversal of 1890721251225 is 5221521270981.

It is a happy number.

The square root of 1890721251225 is 1375035.

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

1890721251225 is a `hidden beast` number, since 1 + 8 + 90 + 7 + 21 + 2 + 512 + 25 = 666.

It can be written as a sum of positive squares in 22 ways, for example, as 1868199646041 + 22521605184 = 1366821^2 + 150072^2 .

It is not a de Polignac number, because 1890721251225 - 2²³ = 1890712862617 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 17346066471 + ... + 17346066579.

Almost surely, 2^{1890721251225} is an apocalyptic number.

1890721251225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1890721251225 is the 1375035-th square number.

1890721251225 is the 687518-th centered octagonal number.

It is an amenable number.

1890721251225 is a deficient number, since it is larger than the sum of its proper divisors (1649190098568).

1890721251225 is an frugal number, since it uses more digits than its factorization.

1890721251225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 350 (or 146 counting only the distinct ones).

The product of its (nonzero) digits is 201600, while the sum is 45.

The spelling of 1890721251225 in words is "one trillion, eight hundred ninety billion, seven hundred twenty-one million, two hundred fifty-one thousand, two hundred twenty-five".