400516381 has 4 divisors (see below), whose sum is σ = 400564764. Its totient is φ = 400468000.

The previous prime is 400516343. The next prime is 400516393. The reversal of 400516381 is 183615004.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 337456900 + 63059481 = 18370^2 + 7941^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-400516381 is a prime.

It is a super-2 number, since 2×400516381² = 320826742898674322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400516681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8290 + ... + 29491.

It is an arithmetic number, because the mean of its divisors is an integer number (100141191).

Almost surely, 2^400516381 is an apocalyptic number.

It is an amenable number.

400516381 is a deficient number, since it is larger than the sum of its proper divisors (48383).

400516381 is a wasteful number, since it uses less digits than its factorization.

400516381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48382.

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 400516381 is about 20012.9053612912. The cubic root of 400516381 is about 737.1232240340.

The spelling of 400516381 in words is "four hundred million, five hundred sixteen thousand, three hundred eighty-one".