61333681 has 2 divisors, whose sum is σ = 61333682. Its totient is φ = 61333680.

The previous prime is 61333673. The next prime is 61333687. The reversal of 61333681 is 18633316.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51624225 + 9709456 = 7185^2 + 3116^2 .

It is a cyclic number.

It is not a de Polignac number, because 61333681 - 2³ = 61333673 is a prime.

It is a super-2 number, since 2×61333681² = 7523640850019522, which contains 22 as substring.

It is equal to p_3636481 and since 61333681 and 3636481 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (61333687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30666840 + 30666841.

It is an arithmetic number, because the mean of its divisors is an integer number (30666841).

Almost surely, 2^61333681 is an apocalyptic number.

It is an amenable number.

61333681 is a deficient number, since it is larger than the sum of its proper divisors (1).

61333681 is an equidigital number, since it uses as much as digits as its factorization.

61333681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7776, while the sum is 31.

The square root of 61333681 is about 7831.5822794631. The cubic root of 61333681 is about 394.3661917960.

Adding to 61333681 its reverse (18633316), we get a palindrome (79966997).

The spelling of 61333681 in words is "sixty-one million, three hundred thirty-three thousand, six hundred eighty-one".