21634019 has 8 divisors (see below), whose sum is σ = 24176880. Its totient is φ = 19187200.

The previous prime is 21633973. The next prime is 21634021. The reversal of 21634019 is 91043612.

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 21634019 - 2⁸ = 21633763 is a prime.

It is a super-2 number, since 2×21634019² = 936061556184722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21634079) 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, 23534 + ... + 24435.

It is an arithmetic number, because the mean of its divisors is an integer number (3022110).

Almost surely, 2^21634019 is an apocalyptic number.

21634019 is a deficient number, since it is larger than the sum of its proper divisors (2542861).

21634019 is a wasteful number, since it uses less digits than its factorization.

21634019 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48021.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 21634019 is about 4651.2384372337. The cubic root of 21634019 is about 278.6414590786.

The spelling of 21634019 in words is "twenty-one million, six hundred thirty-four thousand, nineteen".