20309955169 has 9 divisors (see below), whose sum is σ = 23627026737. Its totient is φ = 17407677924.

The previous prime is 20309955161. The next prime is 20309955179. The reversal of 20309955169 is 96155990302.

The square root of 20309955169 is 142513.

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

It is not a de Polignac number, because 20309955169 - 2³ = 20309955161 is a prime.

It is a super-2 number, since 2×20309955169² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20309955161) 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, 987412 + ... + 1007770.

It is an arithmetic number, because the mean of its divisors is an integer number (2625225193).

Almost surely, 2^20309955169 is an apocalyptic number.

20309955169 is the 142513-rd square number.

20309955169 is the 71257-th centered octagonal number.

It is an amenable number.

20309955169 is a deficient number, since it is larger than the sum of its proper divisors (3317071568).

20309955169 is an frugal number, since it uses more digits than its factorization.

20309955169 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40732 (or 20366 counting only the distinct ones).

The product of its (nonzero) digits is 656100, while the sum is 49.

Multiplying 20309955169 by its sum of digits (49), we get a square (995187803281 = 997591²).

20309955169 divided by its sum of digits (49) gives a square (414488881 = 20359²).

The spelling of 20309955169 in words is "twenty billion, three hundred nine million, nine hundred fifty-five thousand, one hundred sixty-nine".