1289020681 has 32 divisors (see below), whose sum is σ = 1469412000. Its totient is φ = 1122508800.

The previous prime is 1289020661. The next prime is 1289020687. The reversal of 1289020681 is 1860209821.

It can be written as a sum of positive squares in 16 ways, for example, as 44342281 + 1244678400 = 6659^2 + 35280^2 .

It is not a de Polignac number, because 1289020681 - 2¹⁵ = 1288987913 is a prime.

It is a super-2 number, since 2×1289020681² = 3323148632091407522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1289020681.

It is not an unprimeable number, because it can be changed into a prime (1289020687) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3693295 + ... + 3693643.

It is an arithmetic number, because the mean of its divisors is an integer number (45919125).

Almost surely, 2^1289020681 is an apocalyptic number.

It is an amenable number.

1289020681 is a deficient number, since it is larger than the sum of its proper divisors (180391319).

1289020681 is a wasteful number, since it uses less digits than its factorization.

1289020681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 589.

The product of its (nonzero) digits is 13824, while the sum is 37.

The square root of 1289020681 is about 35902.9341558597. The cubic root of 1289020681 is about 1088.3116923550.

The spelling of 1289020681 in words is "one billion, two hundred eighty-nine million, twenty thousand, six hundred eighty-one".