20958840 has 96 divisors (see below), whose sum is σ = 77856480. Its totient is φ = 4790016.

The previous prime is 20958829. The next prime is 20958853. The reversal of 20958840 is 4885902.

It is a hoax number, since the sum of its digits (36) 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 (36).

It is a junction number, because it is equal to n+sod(n) for n = 20958795 and 20958804.

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, 1639 + ... + 6678.

It is an arithmetic number, because the mean of its divisors is an integer number (811005).

Almost surely, 2^20958840 is an apocalyptic number.

20958840 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 20958840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38928240).

20958840 is an abundant number, since it is smaller than the sum of its proper divisors (56897640).

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

20958840 is a wasteful number, since it uses less digits than its factorization.

20958840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8341 (or 8334 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 20958840 is about 4578.0825680627. The cubic root of 20958840 is about 275.7120500337.

It can be divided in two parts, 209588 and 40, that added together give a triangular number (209628 = T₆₄₇).

The spelling of 20958840 in words is "twenty million, nine hundred fifty-eight thousand, eight hundred forty".