21634477 has 4 divisors (see below), whose sum is σ = 21755520. Its totient is φ = 21513436.

The previous prime is 21634453. The next prime is 21634537. The reversal of 21634477 is 77443612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21634477 - 2¹⁹ = 21110189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21634427) 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 3 ways as a sum of consecutive naturals, for example, 60253 + ... + 60610.

It is an arithmetic number, because the mean of its divisors is an integer number (5438880).

Almost surely, 2^21634477 is an apocalyptic number.

It is an amenable number.

21634477 is a deficient number, since it is larger than the sum of its proper divisors (121043).

21634477 is a wasteful number, since it uses less digits than its factorization.

21634477 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121042.

The product of its digits is 28224, while the sum is 34.

The square root of 21634477 is about 4651.2876711724. The cubic root of 21634477 is about 278.6434253782.

The spelling of 21634477 in words is "twenty-one million, six hundred thirty-four thousand, four hundred seventy-seven".