1281611625 has 32 divisors (see below), whose sum is σ = 2437264128. Its totient is φ = 585878400.

The previous prime is 1281611599. The next prime is 1281611633. The reversal of 1281611625 is 5261161821.

It is not a de Polignac number, because 1281611625 - 2¹⁶ = 1281546089 is a prime.

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 31 ways as a sum of consecutive naturals, for example, 241492 + ... + 246741.

It is an arithmetic number, because the mean of its divisors is an integer number (76164504).

Almost surely, 2^1281611625 is an apocalyptic number.

1281611625 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1281611625 is a deficient number, since it is larger than the sum of its proper divisors (1155652503).

1281611625 is an equidigital number, since it uses as much as digits as its factorization.

1281611625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 488258 (or 488248 counting only the distinct ones).

The product of its digits is 5760, while the sum is 33.

The square root of 1281611625 is about 35799.6036989238. The cubic root of 1281611625 is about 1086.2225454475. Note that the first 3 decimals are identical.

The spelling of 1281611625 in words is "one billion, two hundred eighty-one million, six hundred eleven thousand, six hundred twenty-five".