20290464 has 72 divisors (see below), whose sum is σ = 58968000. Its totient is φ = 6615168.

The previous prime is 20290463. The next prime is 20290471. The reversal of 20290464 is 46409202.

It is a tau number, because it is divible by the number of its divisors (72).

It is not an unprimeable number, because it can be changed into a prime (20290463) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12787 + ... + 14285.

It is an arithmetic number, because the mean of its divisors is an integer number (819000).

Almost surely, 2^20290464 is an apocalyptic number.

20290464 is a gapful number since it is divisible by the number (24) 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 20290464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29484000).

20290464 is an abundant number, since it is smaller than the sum of its proper divisors (38677536).

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

20290464 is a wasteful number, since it uses less digits than its factorization.

20290464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1562 (or 1551 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 20290464 is about 4504.4937562394. The cubic root of 20290464 is about 272.7495186702.

Adding to 20290464 its reverse (46409202), we get a palindrome (66699666).

The spelling of 20290464 in words is "twenty million, two hundred ninety thousand, four hundred sixty-four".