21007601 has 8 divisors (see below), whose sum is σ = 21851520. Its totient is φ = 20178288.

The previous prime is 21007589. The next prime is 21007627. The reversal of 21007601 is 10670012.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21007601 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21007601.

It is not an unprimeable number, because it can be changed into a prime (21007681) 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, 671 + ... + 6516.

It is an arithmetic number, because the mean of its divisors is an integer number (2731440).

Almost surely, 2^21007601 is an apocalyptic number.

It is an amenable number.

21007601 is a deficient number, since it is larger than the sum of its proper divisors (843919).

21007601 is an equidigital number, since it uses as much as digits as its factorization.

21007601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7303.

The product of its (nonzero) digits is 84, while the sum is 17.

The square root of 21007601 is about 4583.4049570161. The cubic root of 21007601 is about 275.9257002620.

Adding to 21007601 its reverse (10670012), we get a palindrome (31677613).

The spelling of 21007601 in words is "twenty-one million, seven thousand, six hundred one".