21202010020 has 24 divisors (see below), whose sum is σ = 47143293624. Its totient is φ = 7981933056.

The previous prime is 21202010009. The next prime is 21202010057. The reversal of 21202010020 is 2001020212.

It can be written as a sum of positive squares in 4 ways, for example, as 7553695744 + 13648314276 = 86912^2 + 116826^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 21202009979 and 21202010006.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31179087 + ... + 31179766.

It is an arithmetic number, because the mean of its divisors is an integer number (1964303901).

Almost surely, 2^21202010020 is an apocalyptic number.

21202010020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21202010020 is an abundant number, since it is smaller than the sum of its proper divisors (25941283604).

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

21202010020 is a wasteful number, since it uses less digits than its factorization.

21202010020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62358879 (or 62358877 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

Adding to 21202010020 its reverse (2001020212), we get a palindrome (23203030232).

The spelling of 21202010020 in words is "twenty-one billion, two hundred two million, ten thousand, twenty".