61306381 has 2 divisors, whose sum is σ = 61306382. Its totient is φ = 61306380.

The previous prime is 61306361. The next prime is 61306397. The reversal of 61306381 is 18360316.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 53655625 + 7650756 = 7325^2 + 2766^2 .

It is a cyclic number.

It is not a de Polignac number, because 61306381 - 2⁷ = 61306253 is a prime.

It is a super-2 number, since 2×61306381² = 7516944702634322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61306351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30653190 + 30653191.

It is an arithmetic number, because the mean of its divisors is an integer number (30653191).

Almost surely, 2^61306381 is an apocalyptic number.

It is an amenable number.

61306381 is a deficient number, since it is larger than the sum of its proper divisors (1).

61306381 is an equidigital number, since it uses as much as digits as its factorization.

61306381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 61306381 is about 7829.8391426644. The cubic root of 61306381 is about 394.3076715038.

Adding to 61306381 its reverse (18360316), we get a palindrome (79666697).

The spelling of 61306381 in words is "sixty-one million, three hundred six thousand, three hundred eighty-one".