20669040 has 160 divisors (see below), whose sum is σ = 81423360. Its totient is φ = 4720896.

The previous prime is 20669039. The next prime is 20669041. The reversal of 20669040 is 4096602.

It is an interprime number because it is at equal distance from previous prime (20669039) and next prime (20669041).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 20668995 and 20669013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20669041) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 14437 + ... + 15803.

It is an arithmetic number, because the mean of its divisors is an integer number (508896).

Almost surely, 2^20669040 is an apocalyptic number.

20669040 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 20669040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40711680).

20669040 is an abundant number, since it is smaller than the sum of its proper divisors (60754320).

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

20669040 is a wasteful number, since it uses less digits than its factorization.

20669040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1396 (or 1384 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 20669040 is about 4546.3215900330. The cubic root of 20669040 is about 274.4353814871.

The spelling of 20669040 in words is "twenty million, six hundred sixty-nine thousand, forty".