1978133569 has 2 divisors, whose sum is σ = 1978133570. Its totient is φ = 1978133568.

The previous prime is 1978133489. The next prime is 1978133579. The reversal of 1978133569 is 9653318791.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1628929600 + 349203969 = 40360^2 + 18687^2 .

It is an emirp because it is prime and its reverse (9653318791) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1978133569 - 2¹⁷ = 1978002497 is a prime.

It is a super-2 number, since 2×1978133569² = 7826024833609355522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1978133579) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 989066784 + 989066785.

It is an arithmetic number, because the mean of its divisors is an integer number (989066785).

Almost surely, 2^1978133569 is an apocalyptic number.

It is an amenable number.

1978133569 is a deficient number, since it is larger than the sum of its proper divisors (1).

1978133569 is an equidigital number, since it uses as much as digits as its factorization.

1978133569 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1224720, while the sum is 52.

The square root of 1978133569 is about 44476.2135191385. The cubic root of 1978133569 is about 1255.3125508429.

The spelling of 1978133569 in words is "one billion, nine hundred seventy-eight million, one hundred thirty-three thousand, five hundred sixty-nine".