21021130278 has 96 divisors (see below), whose sum is σ = 47976364800. Its totient is φ = 6639217728.

The previous prime is 21021130261. The next prime is 21021130279. The reversal of 21021130278 is 87203112012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021130279) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 31050076 + ... + 31050752.

It is an arithmetic number, because the mean of its divisors is an integer number (499753800).

Almost surely, 2^21021130278 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21021130278, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23988182400).

21021130278 is an abundant number, since it is smaller than the sum of its proper divisors (26955234522).

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

21021130278 is a wasteful number, since it uses less digits than its factorization.

21021130278 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1306 (or 1303 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 27.

The spelling of 21021130278 in words is "twenty-one billion, twenty-one million, one hundred thirty thousand, two hundred seventy-eight".