91278323652961 has 9 divisors (see below), whose sum is σ = 91950770574649. Its totient is φ = 90610759177024.

The previous prime is 91278323652959. The next prime is 91278323653081. The reversal of 91278323652961 is 16925632387219.

It is a happy number.

The square root of 91278323652961 is 9553969.

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

It can be written as a sum of positive squares in 4 ways, for example, as 710364094561 + 90567959558400 = 842831^2 + 9516720^2 .

It is not a de Polignac number, because 91278323652961 - 2¹ = 91278323652959 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 91278323652893 and 91278323652902.

It is not an unprimeable number, because it can be changed into a prime (91278323652911) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1308858885 + ... + 1308928621.

Almost surely, 2^{91278323652961} is an apocalyptic number.

91278323652961 is the 9553969-th square number.

91278323652961 is the 4776985-th centered octagonal number.

It is an amenable number.

91278323652961 is a deficient number, since it is larger than the sum of its proper divisors (672446921688).

91278323652961 is an frugal number, since it uses more digits than its factorization.

91278323652961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139748 (or 69874 counting only the distinct ones).

The product of its digits is 58786560, while the sum is 64.

The spelling of 91278323652961 in words is "ninety-one trillion, two hundred seventy-eight billion, three hundred twenty-three million, six hundred fifty-two thousand, nine hundred sixty-one".