991788414281 has 16 divisors (see below), whose sum is σ = 1137559438080. Its totient is φ = 847041262080.

The previous prime is 991788414277. The next prime is 991788414283. The reversal of 991788414281 is 182414887199.

It is a cyclic number.

It is not a de Polignac number, because 991788414281 - 2² = 991788414277 is a prime.

It is a super-2 number, since 2×991788414281² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (991788414283) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5592485 + ... + 5767101.

It is an arithmetic number, because the mean of its divisors is an integer number (71097464880).

Almost surely, 2^991788414281 is an apocalyptic number.

It is an amenable number.

991788414281 is a deficient number, since it is larger than the sum of its proper divisors (145771023799).

991788414281 is a wasteful number, since it uses less digits than its factorization.

991788414281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 177544.

The product of its digits is 9289728, while the sum is 62.

The spelling of 991788414281 in words is "nine hundred ninety-one billion, seven hundred eighty-eight million, four hundred fourteen thousand, two hundred eighty-one".