106821551 has 2 divisors, whose sum is σ = 106821552. Its totient is φ = 106821550.

The previous prime is 106821487. The next prime is 106821569. The reversal of 106821551 is 155128601.

It is a strong prime.

It is an emirp because it is prime and its reverse (155128601) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 106821551 - 2⁶ = 106821487 is a prime.

It is a super-2 number, since 2×106821551² = 22821687516091202, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (106821751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 53410775 + 53410776.

It is an arithmetic number, because the mean of its divisors is an integer number (53410776).

Almost surely, 2^106821551 is an apocalyptic number.

106821551 is a deficient number, since it is larger than the sum of its proper divisors (1).

106821551 is an equidigital number, since it uses as much as digits as its factorization.

106821551 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2400, while the sum is 29.

The square root of 106821551 is about 10335.4511754446. The cubic root of 106821551 is about 474.4818741889.

The spelling of 106821551 in words is "one hundred six million, eight hundred twenty-one thousand, five hundred fifty-one".