21455303240 has 32 divisors (see below), whose sum is σ = 55170780480. Its totient is φ = 7356103872.

The previous prime is 21455303209. The next prime is 21455303273. The reversal of 21455303240 is 4230355412.

It is a happy number.

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, 38312762 + ... + 38313321.

It is an arithmetic number, because the mean of its divisors is an integer number (1724086890).

Almost surely, 2^21455303240 is an apocalyptic number.

21455303240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21455303240 is an abundant number, since it is smaller than the sum of its proper divisors (33715477240).

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

21455303240 is a wasteful number, since it uses less digits than its factorization.

21455303240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76626101 (or 76626097 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 29.

Adding to 21455303240 its reverse (4230355412), we get a palindrome (25685658652).

The spelling of 21455303240 in words is "twenty-one billion, four hundred fifty-five million, three hundred three thousand, two hundred forty".