21610323644 has 24 divisors (see below), whose sum is σ = 46545313248. Its totient is φ = 8549138880.

The previous prime is 21610323643. The next prime is 21610323649. The reversal of 21610323644 is 44632301612.

It is a self number, because there is not a number n which added to its sum of digits gives 21610323644.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21610323643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29684147 + ... + 29684874.

It is an arithmetic number, because the mean of its divisors is an integer number (1939388052).

Almost surely, 2^21610323644 is an apocalyptic number.

It is an amenable number.

21610323644 is an abundant number, since it is smaller than the sum of its proper divisors (24934989604).

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

21610323644 is a wasteful number, since it uses less digits than its factorization.

21610323644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59369045 (or 59369043 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 32.

The spelling of 21610323644 in words is "twenty-one billion, six hundred ten million, three hundred twenty-three thousand, six hundred forty-four".