21917603540 has 48 divisors (see below), whose sum is σ = 52619922432. Its totient is φ = 7512082176.

The previous prime is 21917603507. The next prime is 21917603551. The reversal of 21917603540 is 4530671912.

It is a junction number, because it is equal to n+sod(n) for n = 21917603494 and 21917603503.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 418664 + ... + 468096.

It is an arithmetic number, because the mean of its divisors is an integer number (1096248384).

Almost surely, 2^21917603540 is an apocalyptic number.

21917603540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21917603540 is an abundant number, since it is smaller than the sum of its proper divisors (30702318892).

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

21917603540 is a wasteful number, since it uses less digits than its factorization.

21917603540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52616 (or 52614 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 38.

The spelling of 21917603540 in words is "twenty-one billion, nine hundred seventeen million, six hundred three thousand, five hundred forty".