85391943961 has 9 divisors (see below), whose sum is σ = 86599354239. Its totient is φ = 84201151536.

The previous prime is 85391943953. The next prime is 85391943971. The reversal of 85391943961 is 16934919358.

It is a happy number.

The square root of 85391943961 is 292219.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 48472627225 + 36919316736 = 220165^2 + 192144^2 .

It is not a de Polignac number, because 85391943961 - 2³ = 85391943953 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 85391943896 and 85391943905.

It is not an unprimeable number, because it can be changed into a prime (85391943911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 21329986 + ... + 21333988.

It is an arithmetic number, because the mean of its divisors is an integer number (9622150471).

Almost surely, 2^85391943961 is an apocalyptic number.

85391943961 is the 292219-th square number.

85391943961 is the 146110-th centered octagonal number.

It is an amenable number.

85391943961 is a deficient number, since it is larger than the sum of its proper divisors (1207410278).

85391943961 is an frugal number, since it uses more digits than its factorization.

85391943961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8152 (or 4076 counting only the distinct ones).

The product of its digits is 6298560, while the sum is 58.

The spelling of 85391943961 in words is "eighty-five billion, three hundred ninety-one million, nine hundred forty-three thousand, nine hundred sixty-one".