61641637 has 2 divisors, whose sum is σ = 61641638. Its totient is φ = 61641636.

The previous prime is 61641611. The next prime is 61641647. The reversal of 61641637 is 73614616.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58997761 + 2643876 = 7681^2 + 1626^2 .

It is a cyclic number.

It is not a de Polignac number, because 61641637 - 2¹⁹ = 61117349 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61641647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30820818 + 30820819.

It is an arithmetic number, because the mean of its divisors is an integer number (30820819).

Almost surely, 2^61641637 is an apocalyptic number.

It is an amenable number.

61641637 is a deficient number, since it is larger than the sum of its proper divisors (1).

61641637 is an equidigital number, since it uses as much as digits as its factorization.

61641637 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18144, while the sum is 34.

The square root of 61641637 is about 7851.2188225778. The cubic root of 61641637 is about 395.0251268532.

The spelling of 61641637 in words is "sixty-one million, six hundred forty-one thousand, six hundred thirty-seven".