400278044381 has 2 divisors, whose sum is σ = 400278044382. Its totient is φ = 400278044380.

The previous prime is 400278044317. The next prime is 400278044399. The reversal of 400278044381 is 183440872004.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 302537401156 + 97740643225 = 550034^2 + 312635^2 .

It is a cyclic number.

It is not a de Polignac number, because 400278044381 - 2⁶ = 400278044317 is a prime.

It is a super-2 number, since 2×400278044381² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400278044311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200139022190 + 200139022191.

It is an arithmetic number, because the mean of its divisors is an integer number (200139022191).

Almost surely, 2^400278044381 is an apocalyptic number.

It is an amenable number.

400278044381 is a deficient number, since it is larger than the sum of its proper divisors (1).

400278044381 is an equidigital number, since it uses as much as digits as its factorization.

400278044381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 172032, while the sum is 41.

The spelling of 400278044381 in words is "four hundred billion, two hundred seventy-eight million, forty-four thousand, three hundred eighty-one".