21912007 has 8 divisors (see below), whose sum is σ = 23736384. Its totient is φ = 20107488.

The previous prime is 21911987. The next prime is 21912013. The reversal of 21912007 is 70021912.

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 21912007 - 2¹⁵ = 21879239 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 (21912017) 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, 2623 + ... + 7120.

It is an arithmetic number, because the mean of its divisors is an integer number (2967048).

Almost surely, 2^21912007 is an apocalyptic number.

21912007 is a deficient number, since it is larger than the sum of its proper divisors (1824377).

21912007 is a wasteful number, since it uses less digits than its factorization.

21912007 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9929.

The product of its (nonzero) digits is 252, while the sum is 22.

The square root of 21912007 is about 4681.0262763629. The cubic root of 21912007 is about 279.8298583693.

Adding to 21912007 its reverse (70021912), we get a palindrome (91933919).

The spelling of 21912007 in words is "twenty-one million, nine hundred twelve thousand, seven".