61638851 has 2 divisors, whose sum is σ = 61638852. Its totient is φ = 61638850.

The previous prime is 61638839. The next prime is 61638859. The reversal of 61638851 is 15883616.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61638851 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (61638859) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30819425 + 30819426.

It is an arithmetic number, because the mean of its divisors is an integer number (30819426).

Almost surely, 2^61638851 is an apocalyptic number.

61638851 is a deficient number, since it is larger than the sum of its proper divisors (1).

61638851 is an equidigital number, since it uses as much as digits as its factorization.

61638851 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34560, while the sum is 38.

The square root of 61638851 is about 7851.0413958914. The cubic root of 61638851 is about 395.0191754831.

The spelling of 61638851 in words is "sixty-one million, six hundred thirty-eight thousand, eight hundred fifty-one".