61521231 has 8 divisors (see below), whose sum is σ = 82086064. Its totient is φ = 40985280.

The previous prime is 61521203. The next prime is 61521233. The reversal of 61521231 is 13212516.

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

It is not a de Polignac number, because 61521231 - 2⁵ = 61521199 is a prime.

It is a super-2 number, since 2×61521231² = 7569723727510722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 61521198 and 61521207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61521233) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1630 + ... + 11211.

It is an arithmetic number, because the mean of its divisors is an integer number (10260758).

Almost surely, 2^61521231 is an apocalyptic number.

61521231 is a deficient number, since it is larger than the sum of its proper divisors (20564833).

61521231 is a wasteful number, since it uses less digits than its factorization.

61521231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14441.

The product of its digits is 360, while the sum is 21.

The square root of 61521231 is about 7843.5470929931. The cubic root of 61521231 is about 394.7677553736.

Adding to 61521231 its reverse (13212516), we get a palindrome (74733747).

The spelling of 61521231 in words is "sixty-one million, five hundred twenty-one thousand, two hundred thirty-one".