21771345102 has 64 divisors (see below), whose sum is σ = 48585821760. Its totient is φ = 6457651200.

The previous prime is 21771345059. The next prime is 21771345107. The reversal of 21771345102 is 20154317712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21771345107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1487902 + ... + 1502462.

It is an arithmetic number, because the mean of its divisors is an integer number (759153465).

Almost surely, 2^21771345102 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21771345102, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24292910880).

21771345102 is an abundant number, since it is smaller than the sum of its proper divisors (26814476658).

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

21771345102 is a wasteful number, since it uses less digits than its factorization.

21771345102 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15269.

The product of its (nonzero) digits is 11760, while the sum is 33.

The spelling of 21771345102 in words is "twenty-one billion, seven hundred seventy-one million, three hundred forty-five thousand, one hundred two".