21541402469 has 2 divisors, whose sum is σ = 21541402470. Its totient is φ = 21541402468.

The previous prime is 21541402411. The next prime is 21541402529. The reversal of 21541402469 is 96420414512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18696460225 + 2844942244 = 136735^2 + 53338^2 .

It is a cyclic number.

It is not a de Polignac number, because 21541402469 - 2⁸ = 21541402213 is a prime.

It is a super-2 number, since 2×21541402469² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21541402369) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10770701234 + 10770701235.

It is an arithmetic number, because the mean of its divisors is an integer number (10770701235).

Almost surely, 2^21541402469 is an apocalyptic number.

It is an amenable number.

21541402469 is a deficient number, since it is larger than the sum of its proper divisors (1).

21541402469 is an equidigital number, since it uses as much as digits as its factorization.

21541402469 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 69120, while the sum is 38.

The spelling of 21541402469 in words is "twenty-one billion, five hundred forty-one million, four hundred two thousand, four hundred sixty-nine".