21308473772 has 6 divisors (see below), whose sum is σ = 37289829108. Its totient is φ = 10654236884.

The previous prime is 21308473721. The next prime is 21308473817. The reversal of 21308473772 is 27737480312.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2663559218 + ... + 2663559225.

It is an arithmetic number, because the mean of its divisors is an integer number (6214971518).

Almost surely, 2^21308473772 is an apocalyptic number.

It is an amenable number.

21308473772 is a deficient number, since it is larger than the sum of its proper divisors (15981355336).

21308473772 is a wasteful number, since it uses less digits than its factorization.

21308473772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5327118447 (or 5327118445 counting only the distinct ones).

The product of its (nonzero) digits is 395136, while the sum is 44.

The spelling of 21308473772 in words is "twenty-one billion, three hundred eight million, four hundred seventy-three thousand, seven hundred seventy-two".