20129549 has 4 divisors (see below), whose sum is σ = 21959520. Its totient is φ = 18299580.

The previous prime is 20129533. The next prime is 20129579. The reversal of 20129549 is 94592102.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20129549 - 2⁴ = 20129533 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20129579) 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, 914969 + ... + 914990.

It is an arithmetic number, because the mean of its divisors is an integer number (5489880).

Almost surely, 2^20129549 is an apocalyptic number.

It is an amenable number.

20129549 is a deficient number, since it is larger than the sum of its proper divisors (1829971).

20129549 is a wasteful number, since it uses less digits than its factorization.

20129549 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1829970.

The product of its (nonzero) digits is 6480, while the sum is 32.

The square root of 20129549 is about 4486.5965943017. The cubic root of 20129549 is about 272.0265842313.

The spelling of 20129549 in words is "twenty million, one hundred twenty-nine thousand, five hundred forty-nine".