396721783 has 4 divisors (see below), whose sum is σ = 405162720. Its totient is φ = 388280848.

The previous prime is 396721763. The next prime is 396721789. The reversal of 396721783 is 387127693.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 387127693 = 499 ⋅775807.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-396721783 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (396721789) 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, 4220398 + ... + 4220491.

It is an arithmetic number, because the mean of its divisors is an integer number (101290680).

Almost surely, 2^396721783 is an apocalyptic number.

396721783 is a deficient number, since it is larger than the sum of its proper divisors (8440937).

396721783 is an equidigital number, since it uses as much as digits as its factorization.

396721783 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8440936.

The product of its digits is 381024, while the sum is 46.

The square root of 396721783 is about 19917.8759660763. The cubic root of 396721783 is about 734.7879333276.

The spelling of 396721783 in words is "three hundred ninety-six million, seven hundred twenty-one thousand, seven hundred eighty-three".