21201501 has 8 divisors (see below), whose sum is σ = 28310464. Its totient is φ = 14113440.

The previous prime is 21201497. The next prime is 21201503. The reversal of 21201501 is 10510212.

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

It is not a de Polignac number, because 21201501 - 2² = 21201497 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 (21201503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2680 + ... + 7041.

It is an arithmetic number, because the mean of its divisors is an integer number (3538808).

Almost surely, 2^21201501 is an apocalyptic number.

It is an amenable number.

21201501 is a deficient number, since it is larger than the sum of its proper divisors (7108963).

21201501 is an equidigital number, since it uses as much as digits as its factorization.

21201501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10451.

The product of its (nonzero) digits is 20, while the sum is 12.

The square root of 21201501 is about 4604.5087685876. The cubic root of 21201501 is about 276.7720324146.

Adding to 21201501 its reverse (10510212), we get a palindrome (31711713).

The spelling of 21201501 in words is "twenty-one million, two hundred one thousand, five hundred one".