21277633 has 4 divisors (see below), whose sum is σ = 22914388. Its totient is φ = 19640880.

The previous prime is 21277621. The next prime is 21277639. The reversal of 21277633 is 33677212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14265729 + 7011904 = 3777^2 + 2648^2 .

It is a cyclic number.

It is not a de Polignac number, because 21277633 - 2⁹ = 21277121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21277595 and 21277604.

It is not an unprimeable number, because it can be changed into a prime (21277639) 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 3 ways as a sum of consecutive naturals, for example, 818358 + ... + 818383.

It is an arithmetic number, because the mean of its divisors is an integer number (5728597).

Almost surely, 2^21277633 is an apocalyptic number.

It is an amenable number.

21277633 is a deficient number, since it is larger than the sum of its proper divisors (1636755).

21277633 is a wasteful number, since it uses less digits than its factorization.

21277633 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1636754.

The product of its digits is 10584, while the sum is 31.

The square root of 21277633 is about 4612.7684745714. The cubic root of 21277633 is about 277.1029215215.

The spelling of 21277633 in words is "twenty-one million, two hundred seventy-seven thousand, six hundred thirty-three".