400780031 has 4 divisors (see below), whose sum is σ = 401649864. Its totient is φ = 399910200.

The previous prime is 400780021. The next prime is 400780033. The reversal of 400780031 is 130087004.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-400780031 is a prime.

It is a super-2 number, since 2×400780031² = 321249266496721922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 400779979 and 400780006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400780033) 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, 434225 + ... + 435146.

It is an arithmetic number, because the mean of its divisors is an integer number (100412466).

Almost surely, 2^400780031 is an apocalyptic number.

400780031 is a deficient number, since it is larger than the sum of its proper divisors (869833).

400780031 is an equidigital number, since it uses as much as digits as its factorization.

400780031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 869832.

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 400780031 is about 20019.4912772528. The cubic root of 400780031 is about 737.2849318685.

The spelling of 400780031 in words is "four hundred million, seven hundred eighty thousand, thirty-one".