21262161 has 8 divisors (see below), whose sum is σ = 29115904. Its totient is φ = 13791600.

The previous prime is 21262147. The next prime is 21262183. The reversal of 21262161 is 16126212.

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

It is not a de Polignac number, because 21262161 - 2¹⁰ = 21261137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21262061) 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, 95665 + ... + 95886.

It is an arithmetic number, because the mean of its divisors is an integer number (3639488).

Almost surely, 2^21262161 is an apocalyptic number.

It is an amenable number.

21262161 is a deficient number, since it is larger than the sum of its proper divisors (7853743).

21262161 is a wasteful number, since it uses less digits than its factorization.

21262161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191591.

The product of its digits is 288, while the sum is 21.

The square root of 21262161 is about 4611.0910856326. The cubic root of 21262161 is about 277.0357402393.

Adding to 21262161 its reverse (16126212), we get a palindrome (37388373).

The spelling of 21262161 in words is "twenty-one million, two hundred sixty-two thousand, one hundred sixty-one".