21427007 has 8 divisors (see below), whose sum is σ = 25552896. Its totient is φ = 17567352.

The previous prime is 21426997. The next prime is 21427013. The reversal of 21427007 is 70072412.

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 21427007 - 2⁴ = 21426991 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21427037) 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, 66383 + ... + 66704.

It is an arithmetic number, because the mean of its divisors is an integer number (3194112).

Almost surely, 2^21427007 is an apocalyptic number.

21427007 is a deficient number, since it is larger than the sum of its proper divisors (4125889).

21427007 is a wasteful number, since it uses less digits than its factorization.

21427007 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133117.

The product of its (nonzero) digits is 784, while the sum is 23.

The square root of 21427007 is about 4628.9315181800. The cubic root of 21427007 is about 277.7498526179.

Adding to 21427007 its reverse (70072412), we get a palindrome (91499419).

The spelling of 21427007 in words is "twenty-one million, four hundred twenty-seven thousand, seven".