1331561025 has 36 divisors (see below), whose sum is σ = 2473317392. Its totient is φ = 710162640.

The previous prime is 1331560991. The next prime is 1331561027. The reversal of 1331561025 is 5201651331.

1331561025 is a `hidden beast` number, since 1 + 33 + 15 + 610 + 2 + 5 = 666.

It is not a de Polignac number, because 1331561025 - 2⁶ = 1331560961 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1331561025.

It is not an unprimeable number, because it can be changed into a prime (1331561027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 103519 + ... + 115668.

Almost surely, 2^1331561025 is an apocalyptic number.

1331561025 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1331561025 is a deficient number, since it is larger than the sum of its proper divisors (1141756367).

1331561025 is an equidigital number, since it uses as much as digits as its factorization.

1331561025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 219212 (or 219195 counting only the distinct ones).

The product of its (nonzero) digits is 2700, while the sum is 27.

The square root of 1331561025 is about 36490.5607657652. The cubic root of 1331561025 is about 1100.1545306317.

The spelling of 1331561025 in words is "one billion, three hundred thirty-one million, five hundred sixty-one thousand, twenty-five".