21612673 has 8 divisors (see below), whose sum is σ = 22429440. Its totient is φ = 20803440.

The previous prime is 21612637. The next prime is 21612677. The reversal of 21612673 is 37621612.

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 21612673 - 2¹³ = 21604481 is a prime.

It is a super-3 number, since 3×21612673³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21612677) 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, 4338 + ... + 7876.

It is an arithmetic number, because the mean of its divisors is an integer number (2803680).

Almost surely, 2^21612673 is an apocalyptic number.

It is an amenable number.

21612673 is a deficient number, since it is larger than the sum of its proper divisors (816767).

21612673 is a wasteful number, since it uses less digits than its factorization.

21612673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3767.

The product of its digits is 3024, while the sum is 28.

The square root of 21612673 is about 4648.9432132475. The cubic root of 21612673 is about 278.5497849751.

The spelling of 21612673 in words is "twenty-one million, six hundred twelve thousand, six hundred seventy-three".