82771865401 has 3 divisors (see below), whose sum is σ = 82772153103. Its totient is φ = 82771577700.

The previous prime is 82771865381. The next prime is 82771865413. The reversal of 82771865401 is 10456817728.

The square root of 82771865401 is 287701.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 70570453801 + 12201411600 = 265651^2 + 110460^2 .

It is not a de Polignac number, because 82771865401 - 2¹¹ = 82771863353 is a prime.

It is a super-2 number, since 2×82771865401² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (82771865461) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 143851 + ... + 431551.

It is an arithmetic number, because the mean of its divisors is an integer number (27590717701).

Almost surely, 2^82771865401 is an apocalyptic number.

82771865401 is the 287701-st square number.

82771865401 is the 143851-st centered octagonal number.

It is an amenable number.

82771865401 is a deficient number, since it is larger than the sum of its proper divisors (287702).

82771865401 is an frugal number, since it uses more digits than its factorization.

82771865401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 575402 (or 287701 counting only the distinct ones).

The product of its (nonzero) digits is 752640, while the sum is 49.

Multiplying 82771865401 by its sum of digits (49), we get a square (4055821404649 = 2013907²).

The spelling of 82771865401 in words is "eighty-two billion, seven hundred seventy-one million, eight hundred sixty-five thousand, four hundred one".