21770721702 has 160 divisors (see below), whose sum is σ = 52826605920. Its totient is φ = 6679895040.

The previous prime is 21770721677. The next prime is 21770721703. The reversal of 21770721702 is 20712707712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21770721703) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 18433552 + ... + 18434732.

It is an arithmetic number, because the mean of its divisors is an integer number (330166287).

Almost surely, 2^21770721702 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21770721702, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26413302960).

21770721702 is an abundant number, since it is smaller than the sum of its proper divisors (31055884218).

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

21770721702 is a wasteful number, since it uses less digits than its factorization.

21770721702 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1380 (or 1371 counting only the distinct ones).

The product of its (nonzero) digits is 19208, while the sum is 36.

The spelling of 21770721702 in words is "twenty-one billion, seven hundred seventy million, seven hundred twenty-one thousand, seven hundred two".