21025469 has 2 divisors, whose sum is σ = 21025470. Its totient is φ = 21025468.

The previous prime is 21025439. The next prime is 21025507. The reversal of 21025469 is 96452012.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17749369 + 3276100 = 4213^2 + 1810^2 .

It is a cyclic number.

It is not a de Polignac number, because 21025469 - 2¹⁶ = 20959933 is a prime.

It is a super-2 number, since 2×21025469² = 884140693339922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21025439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10512734 + 10512735.

It is an arithmetic number, because the mean of its divisors is an integer number (10512735).

Almost surely, 2^21025469 is an apocalyptic number.

It is an amenable number.

21025469 is a deficient number, since it is larger than the sum of its proper divisors (1).

21025469 is an equidigital number, since it uses as much as digits as its factorization.

21025469 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 21025469 is about 4585.3537486218. The cubic root of 21025469 is about 276.0039075621.

The spelling of 21025469 in words is "twenty-one million, twenty-five thousand, four hundred sixty-nine".