21253101 has 8 divisors (see below), whose sum is σ = 28373760. Its totient is φ = 14150592.

The previous prime is 21253093. The next prime is 21253103. The reversal of 21253101 is 10135212.

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

It is not a de Polignac number, because 21253101 - 2³ = 21253093 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21253103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1516 + ... + 6693.

It is an arithmetic number, because the mean of its divisors is an integer number (3546720).

Almost surely, 2^21253101 is an apocalyptic number.

It is an amenable number.

21253101 is a deficient number, since it is larger than the sum of its proper divisors (7120659).

21253101 is an equidigital number, since it uses as much as digits as its factorization.

21253101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9075.

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 21253101 is about 4610.1085670513. The cubic root of 21253101 is about 276.9963855002.

Adding to 21253101 its reverse (10135212), we get a palindrome (31388313).

The spelling of 21253101 in words is "twenty-one million, two hundred fifty-three thousand, one hundred one".