21250640344 has 8 divisors (see below), whose sum is σ = 39844950660. Its totient is φ = 10625320168.

The previous prime is 21250640317. The next prime is 21250640351. The reversal of 21250640344 is 44304605212.

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-3 number, since 3×21250640344³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1328165014 + ... + 1328165029.

Almost surely, 2^21250640344 is an apocalyptic number.

It is an amenable number.

21250640344 is a deficient number, since it is larger than the sum of its proper divisors (18594310316).

21250640344 is a wasteful number, since it uses less digits than its factorization.

21250640344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2656330049 (or 2656330045 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 31.

The spelling of 21250640344 in words is "twenty-one billion, two hundred fifty million, six hundred forty thousand, three hundred forty-four".