81462700897561 has 27 divisors (see below), whose sum is σ = 84773620118271. Its totient is φ = 78279410620944.

The previous prime is 81462700897537. The next prime is 81462700897577. The reversal of 81462700897561 is 16579800726418.

The square root of 81462700897561 is 9025669.

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., 72893943462025 + 8568757435536 = 8537795^2 + 2927244^2 .

It is not a de Polignac number, because 81462700897561 - 2¹³ = 81462700889369 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81462700897493 and 81462700897502.

It is not an unprimeable number, because it can be changed into a prime (81462700897511) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 27717828030 + ... + 27717830968.

Almost surely, 2^{81462700897561} is an apocalyptic number.

81462700897561 is the 9025669-th square number.

81462700897561 is the 4512835-th centered octagonal number.

It is an amenable number.

81462700897561 is a deficient number, since it is larger than the sum of its proper divisors (3310919220710).

81462700897561 is an frugal number, since it uses more digits than its factorization.

81462700897561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6118 (or 3059 counting only the distinct ones).

The product of its (nonzero) digits is 40642560, while the sum is 64.

The spelling of 81462700897561 in words is "eighty-one trillion, four hundred sixty-two billion, seven hundred million, eight hundred ninety-seven thousand, five hundred sixty-one".