20456722729 has 9 divisors (see below), whose sum is σ = 20610474231. Its totient is φ = 20304112920.

The previous prime is 20456722681. The next prime is 20456722789. The reversal of 20456722729 is 92722765402.

The square root of 20456722729 is 143027.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 5996179225 + 14460543504 = 77435^2 + 120252^2 .

It is not a de Polignac number, because 20456722729 - 2¹¹ = 20456720681 is a prime.

It is a super-2 number, since 2×20456722729² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20456722789) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 22454784 + ... + 22455694.

Almost surely, 2^20456722729 is an apocalyptic number.

20456722729 is the 143027-th square number.

20456722729 is the 71514-th centered octagonal number.

It is an amenable number.

20456722729 is a deficient number, since it is larger than the sum of its proper divisors (153751502).

20456722729 is an frugal number, since it uses more digits than its factorization.

20456722729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2136 (or 1068 counting only the distinct ones).

The product of its (nonzero) digits is 846720, while the sum is 46.

The spelling of 20456722729 in words is "twenty billion, four hundred fifty-six million, seven hundred twenty-two thousand, seven hundred twenty-nine".