20840651 has 8 divisors (see below), whose sum is σ = 22588944. Its totient is φ = 19113120.

The previous prime is 20840639. The next prime is 20840653. The reversal of 20840651 is 15604802.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20840651 - 2¹⁴ = 20824267 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20840651.

It is not an unprimeable number, because it can be changed into a prime (20840653) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3065 + ... + 7146.

It is an arithmetic number, because the mean of its divisors is an integer number (2823618).

Almost surely, 2^20840651 is an apocalyptic number.

20840651 is a deficient number, since it is larger than the sum of its proper divisors (1748293).

20840651 is a wasteful number, since it uses less digits than its factorization.

20840651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10381.

The product of its (nonzero) digits is 1920, while the sum is 26.

The square root of 20840651 is about 4565.1561857181. The cubic root of 20840651 is about 275.1928168406.

The spelling of 20840651 in words is "twenty million, eight hundred forty thousand, six hundred fifty-one".