1149640981 has 2 divisors, whose sum is σ = 1149640982. Its totient is φ = 1149640980.

The previous prime is 1149640979. The next prime is 1149641021. The reversal of 1149640981 is 1890469411.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 723879025 + 425761956 = 26905^2 + 20634^2 .

It is a cyclic number.

It is not a de Polignac number, because 1149640981 - 2¹ = 1149640979 is a prime.

It is a super-2 number, since 2×1149640981² = 2643348770389284722, which contains 22 as substring.

Together with 1149640979, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1149640951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 574820490 + 574820491.

It is an arithmetic number, because the mean of its divisors is an integer number (574820491).

Almost surely, 2^1149640981 is an apocalyptic number.

It is an amenable number.

1149640981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1149640981 is an equidigital number, since it uses as much as digits as its factorization.

1149640981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 62208, while the sum is 43.

The square root of 1149640981 is about 33906.3560560553. The cubic root of 1149640981 is about 1047.5805156050.

The spelling of 1149640981 in words is "one billion, one hundred forty-nine million, six hundred forty thousand, nine hundred eighty-one".