1625163221 has 12 divisors (see below), whose sum is σ = 1820048076. Its totient is φ = 1449539520.

The previous prime is 1625163181. The next prime is 1625163223. The reversal of 1625163221 is 1223615261.

It can be written as a sum of positive squares in 2 ways, for example, as 694059025 + 931104196 = 26345^2 + 30514^2 .

It is not a de Polignac number, because 1625163221 - 2¹⁸ = 1624901077 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1625163223) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 120296 + ... + 133121.

It is an arithmetic number, because the mean of its divisors is an integer number (151670673).

Almost surely, 2^1625163221 is an apocalyptic number.

1625163221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1625163221 is a deficient number, since it is larger than the sum of its proper divisors (194884855).

1625163221 is a wasteful number, since it uses less digits than its factorization.

1625163221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 253492 (or 253481 counting only the distinct ones).

The product of its digits is 4320, while the sum is 29.

The square root of 1625163221 is about 40313.3131979995. The cubic root of 1625163221 is about 1175.7067053322.

Adding to 1625163221 its reverse (1223615261), we get a palindrome (2848778482).

The spelling of 1625163221 in words is "one billion, six hundred twenty-five million, one hundred sixty-three thousand, two hundred twenty-one".