21254416669 has 4 divisors (see below), whose sum is σ = 21464856540. Its totient is φ = 21043976800.

The previous prime is 21254416663. The next prime is 21254416693. The reversal of 21254416669 is 96661445212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18834268644 + 2420148025 = 137238^2 + 49195^2 .

It is a cyclic number.

It is not a de Polignac number, because 21254416669 - 2¹⁵ = 21254383901 is a prime.

It is a super-2 number, since 2×21254416669² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21254416663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 105219784 + ... + 105219985.

It is an arithmetic number, because the mean of its divisors is an integer number (5366214135).

Almost surely, 2^21254416669 is an apocalyptic number.

It is an amenable number.

21254416669 is a deficient number, since it is larger than the sum of its proper divisors (210439871).

21254416669 is a wasteful number, since it uses less digits than its factorization.

21254416669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210439870.

The product of its digits is 622080, while the sum is 46.

The spelling of 21254416669 in words is "twenty-one billion, two hundred fifty-four million, four hundred sixteen thousand, six hundred sixty-nine".