21101493 has 16 divisors (see below), whose sum is σ = 32219136. Its totient is φ = 12033840.

The previous prime is 21101461. The next prime is 21101503. The reversal of 21101493 is 39410112.

It is not a de Polignac number, because 21101493 - 2⁵ = 21101461 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101293) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18580 + ... + 19682.

It is an arithmetic number, because the mean of its divisors is an integer number (2013696).

Almost surely, 2^21101493 is an apocalyptic number.

It is an amenable number.

21101493 is a deficient number, since it is larger than the sum of its proper divisors (11117643).

21101493 is a wasteful number, since it uses less digits than its factorization.

21101493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2024.

The product of its (nonzero) digits is 216, while the sum is 21.

The square root of 21101493 is about 4593.6361414461. The cubic root of 21101493 is about 276.3361662099.

The spelling of 21101493 in words is "twenty-one million, one hundred one thousand, four hundred ninety-three".