117920981 has 2 divisors, whose sum is σ = 117920982. Its totient is φ = 117920980.

The previous prime is 117920963. The next prime is 117920987. The reversal of 117920981 is 189029711.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77598481 + 40322500 = 8809^2 + 6350^2 .

It is a cyclic number.

It is not a de Polignac number, because 117920981 - 2¹⁰ = 117919957 is a prime.

It is a super-2 number, since 2×117920981² = 27810715520004722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (117920987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 58960490 + 58960491.

It is an arithmetic number, because the mean of its divisors is an integer number (58960491).

Almost surely, 2^117920981 is an apocalyptic number.

It is an amenable number.

117920981 is a deficient number, since it is larger than the sum of its proper divisors (1).

117920981 is an equidigital number, since it uses as much as digits as its factorization.

117920981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9072, while the sum is 38.

The square root of 117920981 is about 10859.1427378039. The cubic root of 117920981 is about 490.3773034571.

The spelling of 117920981 in words is "one hundred seventeen million, nine hundred twenty thousand, nine hundred eighty-one".