21076881 has 32 divisors (see below), whose sum is σ = 33903360. Its totient is φ = 11391744.

The previous prime is 21076879. The next prime is 21076883. The reversal of 21076881 is 18867012.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21076879) and next prime (21076883).

It is not a de Polignac number, because 21076881 - 2¹ = 21076879 is a prime.

It is a super-2 number, since 2×21076881² = 888469825376322, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21076883) 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 31 ways as a sum of consecutive naturals, for example, 31951 + ... + 32603.

It is an arithmetic number, because the mean of its divisors is an integer number (1059480).

Almost surely, 2^21076881 is an apocalyptic number.

21076881 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21076881 is a deficient number, since it is larger than the sum of its proper divisors (12826479).

21076881 is a wasteful number, since it uses less digits than its factorization.

21076881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 745.

The product of its (nonzero) digits is 5376, while the sum is 33.

The square root of 21076881 is about 4590.9564362995. The cubic root of 21076881 is about 276.2286883227.

The spelling of 21076881 in words is "twenty-one million, seventy-six thousand, eight hundred eighty-one".