20447429 has 4 divisors (see below), whose sum is σ = 20501760. Its totient is φ = 20393100.

The previous prime is 20447423. The next prime is 20447443. The reversal of 20447429 is 92474402.

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 a de Polignac number, because none of the positive numbers 2^k-20447429 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20447395 and 20447404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20447423) 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, 26597 + ... + 27354.

It is an arithmetic number, because the mean of its divisors is an integer number (5125440).

Almost surely, 2^20447429 is an apocalyptic number.

It is an amenable number.

20447429 is a deficient number, since it is larger than the sum of its proper divisors (54331).

20447429 is an equidigital number, since it uses as much as digits as its factorization.

20447429 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54330.

The product of its (nonzero) digits is 16128, while the sum is 32.

The square root of 20447429 is about 4521.8833465714. The cubic root of 20447429 is about 273.4510338161.

The spelling of 20447429 in words is "twenty million, four hundred forty-seven thousand, four hundred twenty-nine".