400729 has 16 divisors (see below), whose sum is σ = 506880. Its totient is φ = 308880.

The previous prime is 400723. The next prime is 400739. The reversal of 400729 is 927004.

It is a cyclic number.

It is not a de Polignac number, because 400729 - 2³ = 400721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (400721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2994 + ... + 3124.

It is an arithmetic number, because the mean of its divisors is an integer number (31680).

2⁴⁰⁰⁷²⁹ is an apocalyptic number.

It is an amenable number.

400729 is a deficient number, since it is larger than the sum of its proper divisors (106151).

400729 is a wasteful number, since it uses less digits than its factorization.

400729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 180.

The product of its (nonzero) digits is 504, while the sum is 22.

The square root of 400729 is about 633.0315947881. The cubic root of 400729 is about 73.7253637907.

It can be divided in two parts, 400 and 729, that multiplied together give a square (291600 = 540²).

The spelling of 400729 in words is "four hundred thousand, seven hundred twenty-nine".