21351469 has 2 divisors, whose sum is σ = 21351470. Its totient is φ = 21351468.

The previous prime is 21351457. The next prime is 21351503. The reversal of 21351469 is 96415312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19474569 + 1876900 = 4413^2 + 1370^2 .

It is a cyclic number.

It is not a de Polignac number, because 21351469 - 2¹⁹ = 20827181 is a prime.

It is a super-2 number, since 2×21351469² = 911770456915922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21351469.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21355469) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10675734 + 10675735.

It is an arithmetic number, because the mean of its divisors is an integer number (10675735).

Almost surely, 2^21351469 is an apocalyptic number.

It is an amenable number.

21351469 is a deficient number, since it is larger than the sum of its proper divisors (1).

21351469 is an equidigital number, since it uses as much as digits as its factorization.

21351469 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6480, while the sum is 31.

The square root of 21351469 is about 4620.7649799573. The cubic root of 21351469 is about 277.4230785364.

The spelling of 21351469 in words is "twenty-one million, three hundred fifty-one thousand, four hundred sixty-nine".