21491760006 has 24 divisors (see below), whose sum is σ = 46799485200. Its totient is φ = 7127919216.

The previous prime is 21491759999. The next prime is 21491760007. The reversal of 21491760006 is 60006719412.

21491760006 is a `hidden beast` number, since 2 + 1 + 49 + 1 + 7 + 600 + 0 + 6 = 666.

It is a super-2 number, since 2×21491760006² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21491760007) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2996385 + ... + 3003548.

It is an arithmetic number, because the mean of its divisors is an integer number (1949978550).

Almost surely, 2^21491760006 is an apocalyptic number.

21491760006 is an abundant number, since it is smaller than the sum of its proper divisors (25307725194).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21491760006 is a wasteful number, since it uses less digits than its factorization.

21491760006 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6000140 (or 6000137 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The spelling of 21491760006 in words is "twenty-one billion, four hundred ninety-one million, seven hundred sixty thousand, six".