400771721 has 4 divisors (see below), whose sum is σ = 458024832. Its totient is φ = 343518612.

The previous prime is 400771663. The next prime is 400771727. The reversal of 400771721 is 127177004.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-400771721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (400771727) 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, 28626545 + ... + 28626558.

It is an arithmetic number, because the mean of its divisors is an integer number (114506208).

Almost surely, 2^400771721 is an apocalyptic number.

It is an amenable number.

400771721 is a deficient number, since it is larger than the sum of its proper divisors (57253111).

400771721 is an equidigital number, since it uses as much as digits as its factorization.

400771721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57253110.

The product of its (nonzero) digits is 2744, while the sum is 29.

The square root of 400771721 is about 20019.2837284454. The cubic root of 400771721 is about 737.2798360723.

The spelling of 400771721 in words is "four hundred million, seven hundred seventy-one thousand, seven hundred twenty-one".