106821555 has 8 divisors (see below), whose sum is σ = 170914512. Its totient is φ = 56971488.

The previous prime is 106821551. The next prime is 106821569. The reversal of 106821555 is 555128601.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 106821555 - 2² = 106821551 is a prime.

It is a super-2 number, since 2×106821555² = 22821689225236050, which contains 22 as substring.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (106821551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3560704 + ... + 3560733.

It is an arithmetic number, because the mean of its divisors is an integer number (21364314).

Almost surely, 2^106821555 is an apocalyptic number.

106821555 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

106821555 is a deficient number, since it is larger than the sum of its proper divisors (64092957).

106821555 is an equidigital number, since it uses as much as digits as its factorization.

106821555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7121445.

The product of its (nonzero) digits is 12000, while the sum is 33.

The square root of 106821555 is about 10335.4513689534. The cubic root of 106821555 is about 474.4818801114.

The spelling of 106821555 in words is "one hundred six million, eight hundred twenty-one thousand, five hundred fifty-five".