20878291 has 8 divisors (see below), whose sum is σ = 23892480. Its totient is φ = 17872008.

The previous prime is 20878267. The next prime is 20878303. The reversal of 20878291 is 19287802.

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

It is not a de Polignac number, because 20878291 - 2⁷ = 20878163 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 20878291.

It is not an unprimeable number, because it can be changed into a prime (20878201) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5670 + ... + 8596.

It is an arithmetic number, because the mean of its divisors is an integer number (2986560).

Almost surely, 2^20878291 is an apocalyptic number.

20878291 is a deficient number, since it is larger than the sum of its proper divisors (3014189).

20878291 is a wasteful number, since it uses less digits than its factorization.

20878291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3953.

The product of its (nonzero) digits is 16128, while the sum is 37.

The square root of 20878291 is about 4569.2768574469. The cubic root of 20878291 is about 275.3583911295.

The spelling of 20878291 in words is "twenty million, eight hundred seventy-eight thousand, two hundred ninety-one".