400031134721 has 4 divisors (see below), whose sum is σ = 400395795012. Its totient is φ = 399666474432.

The previous prime is 400031134697. The next prime is 400031134729. The reversal of 400031134721 is 127431130004.

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

It can be written as a sum of positive squares in 2 ways, for example, as 82504519696 + 317526615025 = 287236^2 + 563495^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-400031134721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (400031134729) 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, 182328500 + ... + 182330693.

It is an arithmetic number, because the mean of its divisors is an integer number (100098948753).

Almost surely, 2^400031134721 is an apocalyptic number.

It is an amenable number.

400031134721 is a deficient number, since it is larger than the sum of its proper divisors (364660291).

400031134721 is a wasteful number, since it uses less digits than its factorization.

400031134721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 364660290.

The product of its (nonzero) digits is 2016, while the sum is 26.

Adding to 400031134721 its reverse (127431130004), we get a palindrome (527462264725).

The spelling of 400031134721 in words is "four hundred billion, thirty-one million, one hundred thirty-four thousand, seven hundred twenty-one".