1640231777 has 4 divisors (see below), whose sum is σ = 1640369856. Its totient is φ = 1640093700.

The previous prime is 1640231767. The next prime is 1640231779. The reversal of 1640231777 is 7771320461.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1640231777 - 2³⁰ = 566489953 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1640231777.

It is not an unprimeable number, because it can be changed into a prime (1640231779) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49349 + ... + 75602.

It is an arithmetic number, because the mean of its divisors is an integer number (410092464).

Almost surely, 2^1640231777 is an apocalyptic number.

It is an amenable number.

1640231777 is a deficient number, since it is larger than the sum of its proper divisors (138079).

1640231777 is a wasteful number, since it uses less digits than its factorization.

1640231777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138078.

The product of its (nonzero) digits is 49392, while the sum is 38.

The square root of 1640231777 is about 40499.7750240665. The cubic root of 1640231777 is about 1179.3292599548.

The spelling of 1640231777 in words is "one billion, six hundred forty million, two hundred thirty-one thousand, seven hundred seventy-seven".