21130061 has 4 divisors (see below), whose sum is σ = 21141312. Its totient is φ = 21118812.

The previous prime is 21130049. The next prime is 21130073. The reversal of 21130061 is 16003112.

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, and also a brilliant number, because the two primes have the same length.

It is an interprime number because it is at equal distance from previous prime (21130049) and next prime (21130073).

It is a cyclic number.

It is not a de Polignac number, because 21130061 - 2¹⁰ = 21129037 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21130001) 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, 2051 + ... + 6816.

It is an arithmetic number, because the mean of its divisors is an integer number (5285328).

Almost surely, 2^21130061 is an apocalyptic number.

It is an amenable number.

21130061 is a deficient number, since it is larger than the sum of its proper divisors (11251).

21130061 is an equidigital number, since it uses as much as digits as its factorization.

21130061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11250.

The product of its (nonzero) digits is 36, while the sum is 14.

The square root of 21130061 is about 4596.7446089597. The cubic root of 21130061 is about 276.4608147629.

Adding to 21130061 its reverse (16003112), we get a palindrome (37133173).

The spelling of 21130061 in words is "twenty-one million, one hundred thirty thousand, sixty-one".