21077597 has 4 divisors (see below), whose sum is σ = 21392256. Its totient is φ = 20762940.

The previous prime is 21077561. The next prime is 21077599. The reversal of 21077597 is 79577012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21077597 - 2¹⁸ = 20815453 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21077597.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21077599) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 157229 + ... + 157362.

It is an arithmetic number, because the mean of its divisors is an integer number (5348064).

Almost surely, 2^21077597 is an apocalyptic number.

It is an amenable number.

21077597 is a deficient number, since it is larger than the sum of its proper divisors (314659).

21077597 is an equidigital number, since it uses as much as digits as its factorization.

21077597 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 314658.

The product of its (nonzero) digits is 30870, while the sum is 38.

The square root of 21077597 is about 4591.0344150311. The cubic root of 21077597 is about 276.2318161970.

The spelling of 21077597 in words is "twenty-one million, seventy-seven thousand, five hundred ninety-seven".