23909509129 has 9 divisors (see below), whose sum is σ = 26282569831. Its totient is φ = 21734371120.

The previous prime is 23909509109. The next prime is 23909509139. The reversal of 23909509129 is 92190590932.

It is a happy number.

The square root of 23909509129 is 154627.

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., 759278025 + 23150231104 = 27555^2 + 152152^2 .

It is not a de Polignac number, because 23909509129 - 2¹⁷ = 23909378057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (23909509109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1693869 + ... + 1707925.

Almost surely, 2^23909509129 is an apocalyptic number.

23909509129 is the 154627-th square number.

23909509129 is the 77314-th centered octagonal number.

It is an amenable number.

23909509129 is a deficient number, since it is larger than the sum of its proper divisors (2373060702).

23909509129 is an frugal number, since it uses more digits than its factorization.

23909509129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28136 (or 14068 counting only the distinct ones).

The product of its (nonzero) digits is 393660, while the sum is 49.

Multiplying 23909509129 by its sum of digits (49), we get a square (1171565947321 = 1082389²).

The spelling of 23909509129 in words is "twenty-three billion, nine hundred nine million, five hundred nine thousand, one hundred twenty-nine".