20669280 has 144 divisors (see below), whose sum is σ = 69627600. Its totient is φ = 5152768.

The previous prime is 20669269. The next prime is 20669291. The reversal of 20669280 is 8296602.

It is an interprime number because it is at equal distance from previous prime (20669269) and next prime (20669291).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 138646 + ... + 138794.

It is an arithmetic number, because the mean of its divisors is an integer number (483525).

Almost surely, 2^20669280 is an apocalyptic number.

20669280 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 20669280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34813800).

20669280 is an abundant number, since it is smaller than the sum of its proper divisors (48958320).

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

20669280 is a wasteful number, since it uses less digits than its factorization.

20669280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201 (or 176 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 20669280 is about 4546.3479849215. The cubic root of 20669280 is about 274.4364436915.

The spelling of 20669280 in words is "twenty million, six hundred sixty-nine thousand, two hundred eighty".