20723456 has 54 divisors (see below), whose sum is σ = 44886240. Its totient is φ = 9544704.

The previous prime is 20723453. The next prime is 20723473. The reversal of 20723456 is 65432702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20723453) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 43025 + ... + 43503.

Almost surely, 2^20723456 is an apocalyptic number.

20723456 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20723456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22443120).

20723456 is an abundant number, since it is smaller than the sum of its proper divisors (24162784).

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

20723456 is an equidigital number, since it uses as much as digits as its factorization.

20723456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 521 (or 494 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 29.

The square root of 20723456 is about 4552.3022746738. The cubic root of 20723456 is about 274.6760085217.

The spelling of 20723456 in words is "twenty million, seven hundred twenty-three thousand, four hundred fifty-six".