1299169681 has 2 divisors, whose sum is σ = 1299169682. Its totient is φ = 1299169680.

The previous prime is 1299169633. The next prime is 1299169687. The reversal of 1299169681 is 1869619921.

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., 1284577281 + 14592400 = 35841^2 + 3820^2 .

It is a cyclic number.

It is not a de Polignac number, because 1299169681 - 2¹¹ = 1299167633 is a prime.

It is a super-2 number, since 2×1299169681² = 3375683720059283522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1299169687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 649584840 + 649584841.

It is an arithmetic number, because the mean of its divisors is an integer number (649584841).

Almost surely, 2^1299169681 is an apocalyptic number.

It is an amenable number.

1299169681 is a deficient number, since it is larger than the sum of its proper divisors (1).

1299169681 is an equidigital number, since it uses as much as digits as its factorization.

1299169681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 419904, while the sum is 52.

The square root of 1299169681 is about 36043.9964626566. The cubic root of 1299169681 is about 1091.1604735101.

The spelling of 1299169681 in words is "one billion, two hundred ninety-nine million, one hundred sixty-nine thousand, six hundred eighty-one".