400387731 has 4 divisors (see below), whose sum is σ = 533850312. Its totient is φ = 266925152.

The previous prime is 400387727. The next prime is 400387751. The reversal of 400387731 is 137783004.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 400387731 - 2² = 400387727 is a prime.

It is a super-2 number, since 2×400387731² = 320620670270656722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 400387692 and 400387701.

It is not an unprimeable number, because it can be changed into a prime (400387751) 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, 66731286 + ... + 66731291.

It is an arithmetic number, because the mean of its divisors is an integer number (133462578).

Almost surely, 2^400387731 is an apocalyptic number.

400387731 is a deficient number, since it is larger than the sum of its proper divisors (133462581).

400387731 is a wasteful number, since it uses less digits than its factorization.

400387731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133462580.

The product of its (nonzero) digits is 14112, while the sum is 33.

The square root of 400387731 is about 20009.6909271483. The cubic root of 400387731 is about 737.0442917167.

The spelling of 400387731 in words is "four hundred million, three hundred eighty-seven thousand, seven hundred thirty-one".