61551871 has 2 divisors, whose sum is σ = 61551872. Its totient is φ = 61551870.

The previous prime is 61551869. The next prime is 61551881. The reversal of 61551871 is 17815516.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 61551871 - 2¹ = 61551869 is a prime.

Together with 61551869, it forms a pair of twin primes.

It is the 7846-th Hogben number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61551881) by changing a digit.

It is a nontrivial repunit in base 7845.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30775935 + 30775936.

It is an arithmetic number, because the mean of its divisors is an integer number (30775936).

Almost surely, 2^61551871 is an apocalyptic number.

61551871 is a deficient number, since it is larger than the sum of its proper divisors (1).

61551871 is an equidigital number, since it uses as much as digits as its factorization.

61551871 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8400, while the sum is 34.

The square root of 61551871 is about 7845.5000477981. The cubic root of 61551871 is about 394.8332811352.

The spelling of 61551871 in words is "sixty-one million, five hundred fifty-one thousand, eight hundred seventy-one".