8197521407 has 4 divisors (see below), whose sum is σ = 8221145736. Its totient is φ = 8173897080.

The previous prime is 8197521391. The next prime is 8197521439. The reversal of 8197521407 is 7041257918.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 8197521407 - 2⁴ = 8197521391 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8197521307) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11811644 + ... + 11812337.

It is an arithmetic number, because the mean of its divisors is an integer number (2055286434).

Almost surely, 2^8197521407 is an apocalyptic number.

8197521407 is a deficient number, since it is larger than the sum of its proper divisors (23624329).

8197521407 is a wasteful number, since it uses less digits than its factorization.

8197521407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23624328.

The product of its (nonzero) digits is 141120, while the sum is 44.

The square root of 8197521407 is about 90540.1646066540. The cubic root of 8197521407 is about 2016.3264776565.

The spelling of 8197521407 in words is "eight billion, one hundred ninety-seven million, five hundred twenty-one thousand, four hundred seven".