20021775672 has 64 divisors (see below), whose sum is σ = 51390612000. Its totient is φ = 6496501760.

The previous prime is 20021775667. The next prime is 20021775677. The reversal of 20021775672 is 27657712002.

It is an interprime number because it is at equal distance from previous prime (20021775667) and next prime (20021775677).

It is a self number, because there is not a number n which added to its sum of digits gives 20021775672.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021775677) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 419158 + ... + 464474.

Almost surely, 2^20021775672 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20021775672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25695306000).

20021775672 is an abundant number, since it is smaller than the sum of its proper divisors (31368836328).

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

20021775672 is a wasteful number, since it uses less digits than its factorization.

20021775672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45816 (or 45812 counting only the distinct ones).

The product of its (nonzero) digits is 82320, while the sum is 39.

The spelling of 20021775672 in words is "twenty billion, twenty-one million, seven hundred seventy-five thousand, six hundred seventy-two".