20876781 has 8 divisors (see below), whose sum is σ = 28795680. Its totient is φ = 13437872.

The previous prime is 20876771. The next prime is 20876783. The reversal of 20876781 is 18767802.

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

It is a cyclic number.

It is not a de Polignac number, because 20876781 - 2¹⁴ = 20860397 is a prime.

It is a super-2 number, since 2×20876781² = 871679969843922, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20876783) 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, 119895 + ... + 120068.

It is an arithmetic number, because the mean of its divisors is an integer number (3599460).

Almost surely, 2^20876781 is an apocalyptic number.

It is an amenable number.

20876781 is a deficient number, since it is larger than the sum of its proper divisors (7918899).

20876781 is a wasteful number, since it uses less digits than its factorization.

20876781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 239995.

The product of its (nonzero) digits is 37632, while the sum is 39.

The square root of 20876781 is about 4569.1116204356. Note that the first 3 decimals coincide. The cubic root of 20876781 is about 275.3517526360.

The spelling of 20876781 in words is "twenty million, eight hundred seventy-six thousand, seven hundred eighty-one".