21394577 has 4 divisors (see below), whose sum is σ = 22324800. Its totient is φ = 20464356.

The previous prime is 21394573. The next prime is 21394601. The reversal of 21394577 is 77549312.

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 21394577 - 2² = 21394573 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 21394577.

It is not an unprimeable number, because it can be changed into a prime (21394573) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 465077 + ... + 465122.

It is an arithmetic number, because the mean of its divisors is an integer number (5581200).

Almost surely, 2^21394577 is an apocalyptic number.

It is an amenable number.

21394577 is a deficient number, since it is larger than the sum of its proper divisors (930223).

21394577 is an equidigital number, since it uses as much as digits as its factorization.

21394577 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 930222.

The product of its digits is 52920, while the sum is 38.

The square root of 21394577 is about 4625.4272235114. The cubic root of 21394577 is about 277.6096560921.

The spelling of 21394577 in words is "twenty-one million, three hundred ninety-four thousand, five hundred seventy-seven".