1581620025 has 24 divisors (see below), whose sum is σ = 2625394464. Its totient is φ = 840160000.

The previous prime is 1581619999. The next prime is 1581620057. The reversal of 1581620025 is 5200261851.

It is not a de Polignac number, because 1581620025 - 2²⁶ = 1514511161 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1581619974 and 1581620001.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 23184 + ... + 60833.

It is an arithmetic number, because the mean of its divisors is an integer number (109391436).

Almost surely, 2^1581620025 is an apocalyptic number.

1581620025 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1581620025 is a deficient number, since it is larger than the sum of its proper divisors (1043774439).

1581620025 is a wasteful number, since it uses less digits than its factorization.

1581620025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84281 (or 84276 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 30.

The square root of 1581620025 is about 39769.5866837965. The cubic root of 1581620025 is about 1165.1112212455. Note that the first 3 decimals are identical.

Adding to 1581620025 its reverse (5200261851), we get a palindrome (6781881876).

The spelling of 1581620025 in words is "one billion, five hundred eighty-one million, six hundred twenty thousand, twenty-five".