400128793 has 2 divisors, whose sum is σ = 400128794. Its totient is φ = 400128792.

The previous prime is 400128731. The next prime is 400128857. The reversal of 400128793 is 397821004.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 363550489 + 36578304 = 19067^2 + 6048^2 .

It is a cyclic number.

It is not a de Polignac number, because 400128793 - 2¹⁷ = 399997721 is a prime.

It is not a weakly prime, because it can be changed into another prime (400128713) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200064396 + 200064397.

It is an arithmetic number, because the mean of its divisors is an integer number (200064397).

Almost surely, 2^400128793 is an apocalyptic number.

It is an amenable number.

400128793 is a deficient number, since it is larger than the sum of its proper divisors (1).

400128793 is an equidigital number, since it uses as much as digits as its factorization.

400128793 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 400128793 is about 20003.2195658599. The cubic root of 400128793 is about 736.8853708203.

Adding to 400128793 its reverse (397821004), we get a palindrome (797949797).

The spelling of 400128793 in words is "four hundred million, one hundred twenty-eight thousand, seven hundred ninety-three".