21712077648 has 80 divisors (see below), whose sum is σ = 65031373440. Its totient is φ = 6922688256.

The previous prime is 21712077643. The next prime is 21712077649. The reversal of 21712077648 is 84677021712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21712077643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1082661 + ... + 1102532.

It is an arithmetic number, because the mean of its divisors is an integer number (812892168).

Almost surely, 2^21712077648 is an apocalyptic number.

It is an amenable number.

21712077648 is an abundant number, since it is smaller than the sum of its proper divisors (43319295792).

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

21712077648 is a wasteful number, since it uses less digits than its factorization.

21712077648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2185233 (or 2185221 counting only the distinct ones).

The product of its (nonzero) digits is 263424, while the sum is 45.

The spelling of 21712077648 in words is "twenty-one billion, seven hundred twelve million, seventy-seven thousand, six hundred forty-eight".