21234153018 has 64 divisors (see below), whose sum is σ = 47697656832. Its totient is φ = 6257571840.

The previous prime is 21234153007. The next prime is 21234153023. The reversal of 21234153018 is 81035143212.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 189280 + ... + 279812.

It is an arithmetic number, because the mean of its divisors is an integer number (745275888).

Almost surely, 2^21234153018 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21234153018, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23848828416).

21234153018 is an abundant number, since it is smaller than the sum of its proper divisors (26463503814).

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

21234153018 is a wasteful number, since it uses less digits than its factorization.

21234153018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90679.

The product of its (nonzero) digits is 5760, while the sum is 30.

The spelling of 21234153018 in words is "twenty-one billion, two hundred thirty-four million, one hundred fifty-three thousand, eighteen".