40989646681 has 9 divisors (see below), whose sum is σ = 41685183423. Its totient is φ = 40305537720.

The previous prime is 40989646609. The next prime is 40989646729. The reversal of 40989646681 is 18664698904.

The square root of 40989646681 is 202459.

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., 1332907081 + 39656739600 = 36509^2 + 199140^2 .

It is not a de Polignac number, because 40989646681 - 2¹³ = 40989638489 is a prime.

It is a super-2 number, since 2×40989646681² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (61).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40989656681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 12348340 + ... + 12351658.

It is an arithmetic number, because the mean of its divisors is an integer number (4631687047).

Almost surely, 2^40989646681 is an apocalyptic number.

40989646681 is the 202459-th square number.

40989646681 is the 101230-th centered octagonal number.

It is an amenable number.

40989646681 is a deficient number, since it is larger than the sum of its proper divisors (695536742).

40989646681 is an frugal number, since it uses more digits than its factorization.

40989646681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6760 (or 3380 counting only the distinct ones).

The product of its (nonzero) digits is 17915904, while the sum is 61.

The spelling of 40989646681 in words is "forty billion, nine hundred eighty-nine million, six hundred forty-six thousand, six hundred eighty-one".