20429864 has 96 divisors (see below), whose sum is σ = 50752800. Its totient is φ = 7620480.

The previous prime is 20429863. The next prime is 20429873. The reversal of 20429864 is 46892402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20429863) 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 23 ways as a sum of consecutive naturals, for example, 96719 + ... + 96929.

It is an arithmetic number, because the mean of its divisors is an integer number (528675).

Almost surely, 2^20429864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20429864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25376400).

20429864 is an abundant number, since it is smaller than the sum of its proper divisors (30322936).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20429864 is a wasteful number, since it uses less digits than its factorization.

20429864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 263 (or 252 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 35.

The square root of 20429864 is about 4519.9407075757. The cubic root of 20429864 is about 273.3727103029.

The spelling of 20429864 in words is "twenty million, four hundred twenty-nine thousand, eight hundred sixty-four".