21162743280 has 480 divisors, whose sum is σ = 84185088000. Its totient is φ = 4761275904.

The previous prime is 21162743269. The next prime is 21162743291. The reversal of 21162743280 is 8234726112.

It is a happy number.

21162743280 is a `hidden beast` number, since 2 + 1 + 1 + 627 + 4 + 3 + 28 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (21162743269) and next prime (21162743291).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 16545681 + ... + 16546959.

It is an arithmetic number, because the mean of its divisors is an integer number (175385600).

Almost surely, 2^21162743280 is an apocalyptic number.

21162743280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21162743280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42092544000).

21162743280 is an abundant number, since it is smaller than the sum of its proper divisors (63022344720).

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

21162743280 is a wasteful number, since it uses less digits than its factorization.

21162743280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1386 (or 1363 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The spelling of 21162743280 in words is "twenty-one billion, one hundred sixty-two million, seven hundred forty-three thousand, two hundred eighty".