20264640 has 224 divisors, whose sum is σ = 74615040. Its totient is φ = 4608000.

The previous prime is 20264609. The next prime is 20264689. The reversal of 20264640 is 4646202.

It is a hoax number, since the sum of its digits (24) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 20264640.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 200590 + ... + 200690.

Almost surely, 2^20264640 is an apocalyptic number.

20264640 is a gapful number since it is divisible by the number (20) 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 20264640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37307520).

20264640 is an abundant number, since it is smaller than the sum of its proper divisors (54350400).

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

20264640 is a wasteful number, since it uses less digits than its factorization.

20264640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151 (or 141 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 24.

The square root of 20264640 is about 4501.6263727680. The cubic root of 20264640 is about 272.6337586462.

It can be divided in two parts, 2026 and 4640, that added together give a palindrome (6666).

The spelling of 20264640 in words is "twenty million, two hundred sixty-four thousand, six hundred forty".