20777881 has 8 divisors (see below), whose sum is σ = 21329984. Its totient is φ = 20232720.

The previous prime is 20777837. The next prime is 20777899. The reversal of 20777881 is 18877702.

It is a happy number.

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 20777881 - 2⁷ = 20777753 is a prime.

It is a super-2 number, since 2×20777881² = 863440677700322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20777681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4630 + ... + 7936.

It is an arithmetic number, because the mean of its divisors is an integer number (2666248).

Almost surely, 2^20777881 is an apocalyptic number.

It is an amenable number.

20777881 is a deficient number, since it is larger than the sum of its proper divisors (552103).

20777881 is a wasteful number, since it uses less digits than its factorization.

20777881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3471.

The product of its (nonzero) digits is 43904, while the sum is 40.

The square root of 20777881 is about 4558.2760995798. The cubic root of 20777881 is about 274.9162543894.

The spelling of 20777881 in words is "twenty million, seven hundred seventy-seven thousand, eight hundred eighty-one".