220400729 has 4 divisors (see below), whose sum is σ = 220783284. Its totient is φ = 220018176.

The previous prime is 220400723. The next prime is 220400759. The reversal of 220400729 is 927004022.

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 206353225 + 14047504 = 14365^2 + 3748^2 .

It is a cyclic number.

It is not a de Polignac number, because 220400729 - 2²⁰ = 219352153 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 220400698 and 220400707.

It is not an unprimeable number, because it can be changed into a prime (220400723) 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, 190412 + ... + 191565.

It is an arithmetic number, because the mean of its divisors is an integer number (55195821).

Almost surely, 2^220400729 is an apocalyptic number.

It is an amenable number.

220400729 is a deficient number, since it is larger than the sum of its proper divisors (382555).

220400729 is an equidigital number, since it uses as much as digits as its factorization.

220400729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 382554.

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

The square root of 220400729 is about 14845.8994001711. The cubic root of 220400729 is about 604.0473854685.

The spelling of 220400729 in words is "two hundred twenty million, four hundred thousand, seven hundred twenty-nine".