21001444364 has 12 divisors (see below), whose sum is σ = 36753572688. Its totient is φ = 10500423600.

The previous prime is 21001444337. The next prime is 21001444381. The reversal of 21001444364 is 46344410012.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 180554 + ... + 273134.

It is an arithmetic number, because the mean of its divisors is an integer number (3062797724).

Almost surely, 2^21001444364 is an apocalyptic number.

It is an amenable number.

21001444364 is a deficient number, since it is larger than the sum of its proper divisors (15752128324).

21001444364 is a wasteful number, since it uses less digits than its factorization.

21001444364 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149296 (or 149294 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 29.

Adding to 21001444364 its reverse (46344410012), we get a palindrome (67345854376).

The spelling of 21001444364 in words is "twenty-one billion, one million, four hundred forty-four thousand, three hundred sixty-four".