21680221412 has 6 divisors (see below), whose sum is σ = 37940387478. Its totient is φ = 10840110704.

The previous prime is 21680221399. The next prime is 21680221441. The reversal of 21680221412 is 21412208612.

It can be written as a sum of positive squares in only one way, i.e., 16906240576 + 4773980836 = 130024^2 + 69094^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2710027673 + ... + 2710027680.

It is an arithmetic number, because the mean of its divisors is an integer number (6323397913).

Almost surely, 2^21680221412 is an apocalyptic number.

It is an amenable number.

21680221412 is a deficient number, since it is larger than the sum of its proper divisors (16260166066).

21680221412 is a wasteful number, since it uses less digits than its factorization.

21680221412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5420055357 (or 5420055355 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 29.

The spelling of 21680221412 in words is "twenty-one billion, six hundred eighty million, two hundred twenty-one thousand, four hundred twelve".