1647621745 has 16 divisors (see below), whose sum is σ = 2465013888. Its totient is φ = 1027088640.

The previous prime is 1647621739. The next prime is 1647621763. The reversal of 1647621745 is 5471267461.

It is not a de Polignac number, because 1647621745 - 2⁷ = 1647621617 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2139384 + ... + 2140153.

It is an arithmetic number, because the mean of its divisors is an integer number (154063368).

Almost surely, 2^1647621745 is an apocalyptic number.

It is an amenable number.

1647621745 is a deficient number, since it is larger than the sum of its proper divisors (817392143).

1647621745 is a wasteful number, since it uses less digits than its factorization.

1647621745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4279560.

The product of its digits is 282240, while the sum is 43.

The square root of 1647621745 is about 40590.9071714343. The cubic root of 1647621745 is about 1181.0977396014.

The spelling of 1647621745 in words is "one billion, six hundred forty-seven million, six hundred twenty-one thousand, seven hundred forty-five".