21025677 has 4 divisors (see below), whose sum is σ = 28034240. Its totient is φ = 14017116.

The previous prime is 21025639. The next prime is 21025681. The reversal of 21025677 is 77652012.

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 not a de Polignac number, because 21025677 - 2¹⁹ = 20501389 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 (21023677) 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, 3504277 + ... + 3504282.

It is an arithmetic number, because the mean of its divisors is an integer number (7008560).

Almost surely, 2^21025677 is an apocalyptic number.

It is an amenable number.

21025677 is a deficient number, since it is larger than the sum of its proper divisors (7008563).

21025677 is an equidigital number, since it uses as much as digits as its factorization.

21025677 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7008562.

The product of its (nonzero) digits is 5880, while the sum is 30.

The square root of 21025677 is about 4585.3764294766. The cubic root of 21025677 is about 276.0048177063.

Adding to 21025677 its reverse (77652012), we get a palindrome (98677689).

The spelling of 21025677 in words is "twenty-one million, twenty-five thousand, six hundred seventy-seven".