21819622640 has 40 divisors (see below), whose sum is σ = 50742460608. Its totient is φ = 8725812480.

The previous prime is 21819622639. The next prime is 21819622697. The reversal of 21819622640 is 4622691812.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 340169 + ... + 399191.

Almost surely, 2^21819622640 is an apocalyptic number.

21819622640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21819622640 is an abundant number, since it is smaller than the sum of its proper divisors (28922837968).

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

21819622640 is a wasteful number, since it uses less digits than its factorization.

21819622640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63657 (or 63651 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 41.

The spelling of 21819622640 in words is "twenty-one billion, eight hundred nineteen million, six hundred twenty-two thousand, six hundred forty".