21447412440 has 64 divisors (see below), whose sum is σ = 64384070400. Its totient is φ = 5715591552.

The previous prime is 21447412433. The next prime is 21447412447. The reversal of 21447412440 is 4421474412.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21447412433) and next prime (21447412447).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21447412447) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 129759 + ... + 244401.

It is an arithmetic number, because the mean of its divisors is an integer number (1006001100).

Almost surely, 2^21447412440 is an apocalyptic number.

21447412440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21447412440 is an abundant number, since it is smaller than the sum of its proper divisors (42936657960).

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

21447412440 is a wasteful number, since it uses less digits than its factorization.

21447412440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116216 (or 116212 counting only the distinct ones).

The product of its (nonzero) digits is 28672, while the sum is 33.

Adding to 21447412440 its reverse (4421474412), we get a palindrome (25868886852).

The spelling of 21447412440 in words is "twenty-one billion, four hundred forty-seven million, four hundred twelve thousand, four hundred forty".