261230021 has 16 divisors (see below), whose sum is σ = 296615424. Its totient is φ = 228248064.

The previous prime is 261229987. The next prime is 261230033. The reversal of 261230021 is 120032162.

261230021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 261230021 - 2⁶ = 261229957 is a prime.

It is a super-2 number, since 2×261230021² = 136482247743320882, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261230621) 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, 24500 + ... + 33506.

It is an arithmetic number, because the mean of its divisors is an integer number (18538464).

Almost surely, 2^261230021 is an apocalyptic number.

It is an amenable number.

261230021 is a deficient number, since it is larger than the sum of its proper divisors (35385403).

261230021 is a wasteful number, since it uses less digits than its factorization.

261230021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9140.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 261230021 is about 16162.6118248258. The cubic root of 261230021 is about 639.2553358769.

Adding to 261230021 its reverse (120032162), we get a palindrome (381262183).

The spelling of 261230021 in words is "two hundred sixty-one million, two hundred thirty thousand, twenty-one".