21020220104 has 128 divisors (see below), whose sum is σ = 45372096000. Its totient is φ = 9059226624.

The previous prime is 21020220101. The next prime is 21020220107. The reversal of 21020220104 is 40102202012.

It is an interprime number because it is at equal distance from previous prime (21020220101) and next prime (21020220107).

It is a super-3 number, since 3×21020220104³ (a number of 32 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21020220101) 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, 14135249 + ... + 14136735.

It is an arithmetic number, because the mean of its divisors is an integer number (354469500).

Almost surely, 2^21020220104 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 21020220104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22686048000).

21020220104 is an abundant number, since it is smaller than the sum of its proper divisors (24351875896).

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

21020220104 is a wasteful number, since it uses less digits than its factorization.

21020220104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1687 (or 1683 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

Adding to 21020220104 its reverse (40102202012), we get a palindrome (61122422116).

The spelling of 21020220104 in words is "twenty-one billion, twenty million, two hundred twenty thousand, one hundred four".