21429010818 has 48 divisors (see below), whose sum is σ = 46594618200. Its totient is φ = 7117651968.

The previous prime is 21429010817. The next prime is 21429010849. The reversal of 21429010818 is 81801092412.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 21029930289 + 399080529 = 145017^2 + 19977^2 .

It is a super-2 number, since 2×21429010818² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21429010817) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8864746 + ... + 8867162.

Almost surely, 2^21429010818 is an apocalyptic number.

21429010818 is an abundant number, since it is smaller than the sum of its proper divisors (25165607382).

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

21429010818 is a wasteful number, since it uses less digits than its factorization.

21429010818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3971 (or 3968 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 36.

The spelling of 21429010818 in words is "twenty-one billion, four hundred twenty-nine million, ten thousand, eight hundred eighteen".