21673634 has 16 divisors (see below), whose sum is σ = 33506880. Its totient is φ = 10508400.

The previous prime is 21673633. The next prime is 21673651. The reversal of 21673634 is 43637612.

It is a super-3 number, since 3×21673634³ (a number of 23 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21673634.

It is not an unprimeable number, because it can be changed into a prime (21673633) 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, 12152 + ... + 13820.

It is an arithmetic number, because the mean of its divisors is an integer number (2094180).

Almost surely, 2^21673634 is an apocalyptic number.

21673634 is a deficient number, since it is larger than the sum of its proper divisors (11833246).

21673634 is a wasteful number, since it uses less digits than its factorization.

21673634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1865.

The product of its digits is 18144, while the sum is 32.

The square root of 21673634 is about 4655.4950327543. The cubic root of 21673634 is about 278.8114328997.

The spelling of 21673634 in words is "twenty-one million, six hundred seventy-three thousand, six hundred thirty-four".