61331321 has 4 divisors (see below), whose sum is σ = 61516944. Its totient is φ = 61145700.

The previous prime is 61331261. The next prime is 61331323. The reversal of 61331321 is 12313316.

It is a happy number.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61331321 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 61331293 and 61331302.

It is not an unprimeable number, because it can be changed into a prime (61331323) 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, 92315 + ... + 92976.

It is an arithmetic number, because the mean of its divisors is an integer number (15379236).

Almost surely, 2^61331321 is an apocalyptic number.

It is an amenable number.

61331321 is a deficient number, since it is larger than the sum of its proper divisors (185623).

61331321 is a wasteful number, since it uses less digits than its factorization.

61331321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185622.

The product of its digits is 324, while the sum is 20.

The square root of 61331321 is about 7831.4316060347. The cubic root of 61331321 is about 394.3611335847.

Adding to 61331321 its reverse (12313316), we get a palindrome (73644637).

The spelling of 61331321 in words is "sixty-one million, three hundred thirty-one thousand, three hundred twenty-one".