1625665490 has 8 divisors (see below), whose sum is σ = 2926197900. Its totient is φ = 650266192.

The previous prime is 1625665453. The next prime is 1625665493. The reversal of 1625665490 is 945665261.

It can be written as a sum of positive squares in 2 ways, for example, as 1525605481 + 100060009 = 39059^2 + 10003^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1625665493) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 81283265 + ... + 81283284.

Almost surely, 2^1625665490 is an apocalyptic number.

1625665490 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1625665490 is a deficient number, since it is larger than the sum of its proper divisors (1300532410).

1625665490 is a wasteful number, since it uses less digits than its factorization.

1625665490 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162566556.

The product of its (nonzero) digits is 388800, while the sum is 44.

The square root of 1625665490 is about 40319.5422841083. The cubic root of 1625665490 is about 1175.8278132100.

The spelling of 1625665490 in words is "one billion, six hundred twenty-five million, six hundred sixty-five thousand, four hundred ninety".