21536101 has 4 divisors (see below), whose sum is σ = 22669600. Its totient is φ = 20402604.

The previous prime is 21536089. The next prime is 21536107. The reversal of 21536101 is 10163512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21536101 - 2⁵ = 21536069 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19), and also a Moran number because the ratio is a prime number: 1133479 = 21536101 / (2 + 1 + 5 + 3 + 6 + 1 + 0 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21536107) 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, 566721 + ... + 566758.

It is an arithmetic number, because the mean of its divisors is an integer number (5667400).

Almost surely, 2^21536101 is an apocalyptic number.

It is an amenable number.

21536101 is a deficient number, since it is larger than the sum of its proper divisors (1133499).

21536101 is a wasteful number, since it uses less digits than its factorization.

21536101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1133498.

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 21536101 is about 4640.7004859180. The cubic root of 21536101 is about 278.2204357247.

Adding to 21536101 its reverse (10163512), we get a palindrome (31699613).

The spelling of 21536101 in words is "twenty-one million, five hundred thirty-six thousand, one hundred one".