21134472129 has 45 divisors (see below), whose sum is σ = 32756260537. Its totient is φ = 13579374816.

The previous prime is 21134472109. The next prime is 21134472169. The reversal of 21134472129 is 92127443112.

The square root of 21134472129 is 145377.

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

It can be written as a sum of positive squares in 4 ways, for example, as 4169930625 + 16964541504 = 64575^2 + 130248^2 .

It is not a de Polignac number, because 21134472129 - 2¹¹ = 21134470081 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21134472093 and 21134472102.

It is not an unprimeable number, because it can be changed into a prime (21134472109) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 37943119 + ... + 37943675.

Almost surely, 2^21134472129 is an apocalyptic number.

21134472129 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

21134472129 is the 145377-th square number.

21134472129 is the 72689-th centered octagonal number.

It is an amenable number.

21134472129 is a deficient number, since it is larger than the sum of its proper divisors (11621788408).

21134472129 is an frugal number, since it uses more digits than its factorization.

21134472129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1184 (or 589 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

Multiplying 21134472129 by its sum of digits (36), we get a square (760840996644 = 872262²).

The spelling of 21134472129 in words is "twenty-one billion, one hundred thirty-four million, four hundred seventy-two thousand, one hundred twenty-nine".