21310420506 has 16 divisors (see below), whose sum is σ = 44473921344. Its totient is φ = 6794626784.

The previous prime is 21310420487. The next prime is 21310420517. The reversal of 21310420506 is 60502401312.

It is a super-3 number, since 3×21310420506³ (a number of 32 digits) contains 333 as substring.

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, 77211531 + ... + 77211806.

It is an arithmetic number, because the mean of its divisors is an integer number (2779620084).

Almost surely, 2^21310420506 is an apocalyptic number.

21310420506 is an abundant number, since it is smaller than the sum of its proper divisors (23163500838).

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

21310420506 is a wasteful number, since it uses less digits than its factorization.

21310420506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154423365.

The product of its (nonzero) digits is 1440, while the sum is 24.

Adding to 21310420506 its reverse (60502401312), we get a palindrome (81812821818).

The spelling of 21310420506 in words is "twenty-one billion, three hundred ten million, four hundred twenty thousand, five hundred six".