20021201001978 has 256 divisors, whose sum is σ = 48099773030400. Its totient is φ = 5492125900800.

The previous prime is 20021201001943. The next prime is 20021201001979. The reversal of 20021201001978 is 87910010212002.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (20021201001979) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 776032723 + ... + 776058521.

It is an arithmetic number, because the mean of its divisors is an integer number (187889738400).

Almost surely, 2^{20021201001978} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20021201001978, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24049886515200).

20021201001978 is an abundant number, since it is smaller than the sum of its proper divisors (28078572028422).

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

20021201001978 is a wasteful number, since it uses less digits than its factorization.

20021201001978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26253.

The product of its (nonzero) digits is 4032, while the sum is 33.

The spelling of 20021201001978 in words is "twenty trillion, twenty-one billion, two hundred one million, one thousand, nine hundred seventy-eight".