1147918981 has 4 divisors (see below), whose sum is σ = 1252275264. Its totient is φ = 1043562700.

The previous prime is 1147918951. The next prime is 1147919021. The reversal of 1147918981 is 1898197411.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1898197411 = 11 ⋅172563401.

It is a cyclic number.

It is not a de Polignac number, because 1147918981 - 2⁷ = 1147918853 is a prime.

It is a super-2 number, since 2×1147918981² = 2635435973880156722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1147918921) 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, 52178125 + ... + 52178146.

It is an arithmetic number, because the mean of its divisors is an integer number (313068816).

Almost surely, 2^1147918981 is an apocalyptic number.

1147918981 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1147918981 is a deficient number, since it is larger than the sum of its proper divisors (104356283).

1147918981 is a wasteful number, since it uses less digits than its factorization.

1147918981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104356282.

The product of its digits is 145152, while the sum is 49.

The square root of 1147918981 is about 33880.9530710103. The cubic root of 1147918981 is about 1047.0572116323.

The spelling of 1147918981 in words is "one billion, one hundred forty-seven million, nine hundred eighteen thousand, nine hundred eighty-one".