21425007 has 4 divisors (see below), whose sum is σ = 28566680. Its totient is φ = 14283336.

The previous prime is 21425003. The next prime is 21425009. The reversal of 21425007 is 70052412.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21425007 - 2² = 21425003 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 (21425003) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3570832 + ... + 3570837.

It is an arithmetic number, because the mean of its divisors is an integer number (7141670).

Almost surely, 2^21425007 is an apocalyptic number.

21425007 is a deficient number, since it is larger than the sum of its proper divisors (7141673).

21425007 is an equidigital number, since it uses as much as digits as its factorization.

21425007 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7141672.

The product of its (nonzero) digits is 560, while the sum is 21.

The square root of 21425007 is about 4628.7154805626. The cubic root of 21425007 is about 277.7412106116.

Adding to 21425007 its reverse (70052412), we get a palindrome (91477419).

The spelling of 21425007 in words is "twenty-one million, four hundred twenty-five thousand, seven".