21106501 has 8 divisors (see below), whose sum is σ = 22788864. Its totient is φ = 19432560.

The previous prime is 21106471. The next prime is 21106523. The reversal of 21106501 is 10560112.

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 not a de Polignac number, because 21106501 - 2⁷ = 21106373 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 (21106531) 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, 3720 + ... + 7486.

It is an arithmetic number, because the mean of its divisors is an integer number (2848608).

Almost surely, 2^21106501 is an apocalyptic number.

It is an amenable number.

21106501 is a deficient number, since it is larger than the sum of its proper divisors (1682363).

21106501 is a wasteful number, since it uses less digits than its factorization.

21106501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4211.

The product of its (nonzero) digits is 60, while the sum is 16.

The square root of 21106501 is about 4594.1812110538. The cubic root of 21106501 is about 276.3580253592.

Adding to 21106501 its reverse (10560112), we get a palindrome (31666613).

The spelling of 21106501 in words is "twenty-one million, one hundred six thousand, five hundred one".