61738561 has 2 divisors, whose sum is σ = 61738562. Its totient is φ = 61738560.

The previous prime is 61738559. The next prime is 61738571. The reversal of 61738561 is 16583716.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31708161 + 30030400 = 5631^2 + 5480^2 .

It is a cyclic number.

It is not a de Polignac number, because 61738561 - 2¹ = 61738559 is a prime.

Together with 61738559, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 61738561.

It is not a weakly prime, because it can be changed into another prime (61738531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30869280 + 30869281.

It is an arithmetic number, because the mean of its divisors is an integer number (30869281).

Almost surely, 2^61738561 is an apocalyptic number.

It is an amenable number.

61738561 is a deficient number, since it is larger than the sum of its proper divisors (1).

61738561 is an equidigital number, since it uses as much as digits as its factorization.

61738561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30240, while the sum is 37.

The square root of 61738561 is about 7857.3889428995. The cubic root of 61738561 is about 395.2320614693.

The spelling of 61738561 in words is "sixty-one million, seven hundred thirty-eight thousand, five hundred sixty-one".