21601011 has 4 divisors (see below), whose sum is σ = 28801352. Its totient is φ = 14400672.

The previous prime is 21600991. The next prime is 21601061. The reversal of 21601011 is 11010612.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21601011 - 2¹⁰ = 21599987 is a prime.

It is a super-3 number, since 3×21601011³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21601061) 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, 3600166 + ... + 3600171.

It is an arithmetic number, because the mean of its divisors is an integer number (7200338).

Almost surely, 2^21601011 is an apocalyptic number.

21601011 is a deficient number, since it is larger than the sum of its proper divisors (7200341).

21601011 is an equidigital number, since it uses as much as digits as its factorization.

21601011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7200340.

The product of its (nonzero) digits is 12, while the sum is 12.

The square root of 21601011 is about 4647.6887804585. The cubic root of 21601011 is about 278.4996749919.

Adding to 21601011 its reverse (11010612), we get a palindrome (32611623).

The spelling of 21601011 in words is "twenty-one million, six hundred one thousand, eleven".