21441503649 has 4 divisors (see below), whose sum is σ = 28588671536. Its totient is φ = 14294335764.

The previous prime is 21441503581. The next prime is 21441503653. The reversal of 21441503649 is 94630514412.

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 21441503649 - 2⁹ = 21441503137 is a prime.

It is a super-3 number, since 3×21441503649³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21441503749) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3573583939 + ... + 3573583944.

It is an arithmetic number, because the mean of its divisors is an integer number (7147167884).

Almost surely, 2^21441503649 is an apocalyptic number.

It is an amenable number.

21441503649 is a deficient number, since it is larger than the sum of its proper divisors (7147167887).

21441503649 is an equidigital number, since it uses as much as digits as its factorization.

21441503649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7147167886.

The product of its (nonzero) digits is 103680, while the sum is 39.

The spelling of 21441503649 in words is "twenty-one billion, four hundred forty-one million, five hundred three thousand, six hundred forty-nine".