61821871 has 2 divisors, whose sum is σ = 61821872. Its totient is φ = 61821870.

The previous prime is 61821841. The next prime is 61821887. The reversal of 61821871 is 17812816.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 61821871 - 2⁷ = 61821743 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61821811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30910935 + 30910936.

It is an arithmetic number, because the mean of its divisors is an integer number (30910936).

Almost surely, 2^61821871 is an apocalyptic number.

61821871 is a deficient number, since it is larger than the sum of its proper divisors (1).

61821871 is an equidigital number, since it uses as much as digits as its factorization.

61821871 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5376, while the sum is 34.

The square root of 61821871 is about 7862.6885351004. The cubic root of 61821871 is about 395.4097569168.

The spelling of 61821871 in words is "sixty-one million, eight hundred twenty-one thousand, eight hundred seventy-one".