1640097281 has 8 divisors (see below), whose sum is σ = 1680078240. Its totient is φ = 1600522528.

The previous prime is 1640097247. The next prime is 1640097311. The reversal of 1640097281 is 1827900461.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1640097281 is a prime.

It is a super-2 number, since 2×1640097281² = 5379838182287185922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1640097881) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 93371 + ... + 109536.

It is an arithmetic number, because the mean of its divisors is an integer number (210009780).

Almost surely, 2^1640097281 is an apocalyptic number.

It is an amenable number.

1640097281 is a deficient number, since it is larger than the sum of its proper divisors (39980959).

1640097281 is a wasteful number, since it uses less digits than its factorization.

1640097281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203103.

The product of its (nonzero) digits is 24192, while the sum is 38.

The square root of 1640097281 is about 40498.1145363584. The cubic root of 1640097281 is about 1179.2970247943.

The spelling of 1640097281 in words is "one billion, six hundred forty million, ninety-seven thousand, two hundred eighty-one".