1645071757 has 12 divisors (see below), whose sum is σ = 1996858656. Its totient is φ = 1348753560.

The previous prime is 1645071733. The next prime is 1645071773. The reversal of 1645071757 is 7571705461.

It is not a de Polignac number, because 1645071757 - 2⁷ = 1645071629 is a prime.

It is a super-2 number, since 2×1645071757² = 5412522171358134098, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1645071797) 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, 728719 + ... + 730972.

It is an arithmetic number, because the mean of its divisors is an integer number (166404888).

Almost surely, 2^1645071757 is an apocalyptic number.

It is an amenable number.

1645071757 is a deficient number, since it is larger than the sum of its proper divisors (351786899).

1645071757 is a wasteful number, since it uses less digits than its factorization.

1645071757 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1459728 (or 1459721 counting only the distinct ones).

The product of its (nonzero) digits is 205800, while the sum is 43.

The square root of 1645071757 is about 40559.4841806451. The cubic root of 1645071757 is about 1180.4881053074.

The spelling of 1645071757 in words is "one billion, six hundred forty-five million, seventy-one thousand, seven hundred fifty-seven".