1283779561 has 4 divisors (see below), whose sum is σ = 1284015492. Its totient is φ = 1283543632.

The previous prime is 1283779559. The next prime is 1283779583. The reversal of 1283779561 is 1659773821.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 267126336 + 1016653225 = 16344^2 + 31885^2 .

It is a cyclic number.

It is not a de Polignac number, because 1283779561 - 2¹ = 1283779559 is a prime.

It is a super-2 number, since 2×1283779561² = 3296179922482705442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1283771561) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 109606 + ... + 120751.

It is an arithmetic number, because the mean of its divisors is an integer number (321003873).

Almost surely, 2^1283779561 is an apocalyptic number.

It is an amenable number.

1283779561 is a deficient number, since it is larger than the sum of its proper divisors (235931).

1283779561 is an equidigital number, since it uses as much as digits as its factorization.

1283779561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 235930.

The product of its digits is 635040, while the sum is 49.

The square root of 1283779561 is about 35829.8696760119. The cubic root of 1283779561 is about 1086.8346743110.

The spelling of 1283779561 in words is "one billion, two hundred eighty-three million, seven hundred seventy-nine thousand, five hundred sixty-one".