21729464361 has 24 divisors (see below), whose sum is σ = 36042495840. Its totient is φ = 12476246400.

The previous prime is 21729464357. The next prime is 21729464371. The reversal of 21729464361 is 16346492712.

21729464361 is a `hidden beast` number, since 2 + 172 + 9 + 46 + 436 + 1 = 666.

It is not a de Polignac number, because 21729464361 - 2² = 21729464357 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21729464371) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5774160 + ... + 5777921.

It is an arithmetic number, because the mean of its divisors is an integer number (1501770660).

Almost surely, 2^21729464361 is an apocalyptic number.

It is an amenable number.

21729464361 is a deficient number, since it is larger than the sum of its proper divisors (14313031479).

21729464361 is a wasteful number, since it uses less digits than its factorization.

21729464361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11552117 (or 11552114 counting only the distinct ones).

The product of its digits is 435456, while the sum is 45.

The spelling of 21729464361 in words is "twenty-one billion, seven hundred twenty-nine million, four hundred sixty-four thousand, three hundred sixty-one".