21979532477448 has 1344 divisors, whose sum is σ = 82201856434560. Its totient is φ = 5372460048384.

The previous prime is 21979532477411. The next prime is 21979532477501. The reversal of 21979532477448 is 84477423597912.

It is a happy number.

21979532477448 is a `hidden beast` number, since 2 + 1 + 9 + 7 + 9 + 532 + 47 + 7 + 4 + 48 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 335 ways as a sum of consecutive naturals, for example, 7858251186 + ... + 7858253982.

Almost surely, 2^{21979532477448} is an apocalyptic number.

21979532477448 is a gapful number since it is divisible by the number (28) 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 21979532477448, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41100928217280).

21979532477448 is an abundant number, since it is smaller than the sum of its proper divisors (60222323957112).

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

21979532477448 is a wasteful number, since it uses less digits than its factorization.

21979532477448 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2938 (or 2906 counting only the distinct ones).

The product of its digits is 853493760, while the sum is 72.

The spelling of 21979532477448 in words is "twenty-one trillion, nine hundred seventy-nine billion, five hundred thirty-two million, four hundred seventy-seven thousand, four hundred forty-eight".