21421320102 has 480 divisors, whose sum is σ = 63362132064. Its totient is φ = 5356108800.

The previous prime is 21421320091. The next prime is 21421320113. The reversal of 21421320102 is 20102312412.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21421320091) and next prime (21421320113).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 258088153 + ... + 258088235.

Almost surely, 2^21421320102 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21421320102, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31681066032).

21421320102 is an abundant number, since it is smaller than the sum of its proper divisors (41940811962).

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

21421320102 is a wasteful number, since it uses less digits than its factorization.

21421320102 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226 (or 210 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 21421320102 its reverse (20102312412), we get a palindrome (41523632514).

The spelling of 21421320102 in words is "twenty-one billion, four hundred twenty-one million, three hundred twenty thousand, one hundred two".