117821451 has 32 divisors (see below), whose sum is σ = 182004480. Its totient is φ = 67605120.

The previous prime is 117821423. The next prime is 117821467. The reversal of 117821451 is 154128711.

It is not a de Polignac number, because 117821451 - 2⁷ = 117821323 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (117821401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 75091 + ... + 76643.

It is an arithmetic number, because the mean of its divisors is an integer number (5687640).

Almost surely, 2^117821451 is an apocalyptic number.

117821451 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

117821451 is a deficient number, since it is larger than the sum of its proper divisors (64183029).

117821451 is a wasteful number, since it uses less digits than its factorization.

117821451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1608 (or 1586 counting only the distinct ones).

The product of its digits is 2240, while the sum is 30.

The square root of 117821451 is about 10854.5589961085. The cubic root of 117821451 is about 490.2392986373.

The spelling of 117821451 in words is "one hundred seventeen million, eight hundred twenty-one thousand, four hundred fifty-one".