20777281 has 8 divisors (see below), whose sum is σ = 25142400. Its totient is φ = 16761408.

The previous prime is 20777269. The next prime is 20777287. The reversal of 20777281 is 18277702.

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 20777281 - 2⁵ = 20777249 is a prime.

It is a super-2 number, since 2×20777281² = 863390811505922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20777287) 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, 87181 + ... + 87418.

It is an arithmetic number, because the mean of its divisors is an integer number (3142800).

Almost surely, 2^20777281 is an apocalyptic number.

It is an amenable number.

20777281 is a deficient number, since it is larger than the sum of its proper divisors (4365119).

20777281 is a wasteful number, since it uses less digits than its factorization.

20777281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174623.

The product of its (nonzero) digits is 10976, while the sum is 34.

The square root of 20777281 is about 4558.2102847499. The cubic root of 20777281 is about 274.9136081243.

The spelling of 20777281 in words is "twenty million, seven hundred seventy-seven thousand, two hundred eighty-one".