20858040 has 256 divisors, whose sum is σ = 82944000. Its totient is φ = 4561920.

The previous prime is 20858039. The next prime is 20858069. The reversal of 20858040 is 4085802.

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 = 20857995 and 20858013.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 234316 + ... + 234404.

It is an arithmetic number, because the mean of its divisors is an integer number (324000).

Almost surely, 2^20858040 is an apocalyptic number.

20858040 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 20858040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41472000).

20858040 is an abundant number, since it is smaller than the sum of its proper divisors (62085960).

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

20858040 is a wasteful number, since it uses less digits than its factorization.

20858040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147 (or 137 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 27.

The square root of 20858040 is about 4567.0603236655. The cubic root of 20858040 is about 275.2693339254.

The spelling of 20858040 in words is "twenty million, eight hundred fifty-eight thousand, forty".