400020729 has 8 divisors (see below), whose sum is σ = 533602752. Its totient is φ = 266559600.

The previous prime is 400020721. The next prime is 400020739. The reversal of 400020729 is 927020004.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 400020729 - 2³ = 400020721 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 400020699 and 400020708.

It is not an unprimeable number, because it can be changed into a prime (400020721) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22197 + ... + 35954.

It is an arithmetic number, because the mean of its divisors is an integer number (66700344).

Almost surely, 2^400020729 is an apocalyptic number.

It is an amenable number.

400020729 is a deficient number, since it is larger than the sum of its proper divisors (133582023).

400020729 is a wasteful number, since it uses less digits than its factorization.

400020729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60447.

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 400020729 is about 20000.5182182862. The cubic root of 400020729 is about 736.8190272230.

The spelling of 400020729 in words is "four hundred million, twenty thousand, seven hundred twenty-nine".