101521665 has 48 divisors (see below), whose sum is σ = 203164416. Its totient is φ = 45936000.

The previous prime is 101521649. The next prime is 101521669. The reversal of 101521665 is 566125101.

It is a happy number.

It is not a de Polignac number, because 101521665 - 2⁴ = 101521649 is a prime.

It is not an unprimeable number, because it can be changed into a prime (101521669) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 30220 + ... + 33410.

It is an arithmetic number, because the mean of its divisors is an integer number (4232592).

Almost surely, 2^101521665 is an apocalyptic number.

101521665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

101521665 is an abundant number, since it is smaller than the sum of its proper divisors (101642751).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

101521665 is a wasteful number, since it uses less digits than its factorization.

101521665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3310 (or 3307 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 27.

The square root of 101521665 is about 10075.7959983318. The cubic root of 101521665 is about 466.5013561304.

Adding to 101521665 its reverse (566125101), we get a palindrome (667646766).

The spelling of 101521665 in words is "one hundred one million, five hundred twenty-one thousand, six hundred sixty-five".