21260267220 has 24 divisors (see below), whose sum is σ = 59528748384. Its totient is φ = 5669404576.

The previous prime is 21260267191. The next prime is 21260267221. The reversal of 21260267220 is 2276206212.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21260267221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 177168834 + ... + 177168953.

It is an arithmetic number, because the mean of its divisors is an integer number (2480364516).

Almost surely, 2^21260267220 is an apocalyptic number.

21260267220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21260267220 is an abundant number, since it is smaller than the sum of its proper divisors (38268481164).

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

21260267220 is a wasteful number, since it uses less digits than its factorization.

21260267220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 354337799 (or 354337797 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 30.

The spelling of 21260267220 in words is "twenty-one billion, two hundred sixty million, two hundred sixty-seven thousand, two hundred twenty".