20729456 has 40 divisors (see below), whose sum is σ = 46128000. Its totient is φ = 8925120.

The previous prime is 20729419. The next prime is 20729479. The reversal of 20729456 is 65492702.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 245 + ... + 6443.

It is an arithmetic number, because the mean of its divisors is an integer number (1153200).

Almost surely, 2^20729456 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 20729456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23064000).

20729456 is an abundant number, since it is smaller than the sum of its proper divisors (25398544).

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

20729456 is a wasteful number, since it uses less digits than its factorization.

20729456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6237 (or 6231 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 35.

The square root of 20729456 is about 4552.9612341859. The cubic root of 20729456 is about 274.7025146705.

The spelling of 20729456 in words is "twenty million, seven hundred twenty-nine thousand, four hundred fifty-six".