20783490 has 128 divisors (see below), whose sum is σ = 64253952. Its totient is φ = 4181760.

The previous prime is 20783479. The next prime is 20783509. The reversal of 20783490 is 9438702.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax 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, 62625 + ... + 62955.

It is an arithmetic number, because the mean of its divisors is an integer number (501984).

Almost surely, 2^20783490 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20783490, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32126976).

20783490 is an abundant number, since it is smaller than the sum of its proper divisors (43470462).

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

20783490 is a wasteful number, since it uses less digits than its factorization.

20783490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 384.

The product of its (nonzero) digits is 12096, while the sum is 33.

The square root of 20783490 is about 4558.8913125891. The cubic root of 20783490 is about 274.9409900933.

The spelling of 20783490 in words is "twenty million, seven hundred eighty-three thousand, four hundred ninety".