21948309618 has 16 divisors (see below), whose sum is σ = 43916009760. Its totient is φ = 7312871456.

The previous prime is 21948309589. The next prime is 21948309641. The reversal of 21948309618 is 81690384912.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 793203 + ... + 820406.

It is an arithmetic number, because the mean of its divisors is an integer number (2744750610).

Almost surely, 2^21948309618 is an apocalyptic number.

21948309618 is an abundant number, since it is smaller than the sum of its proper divisors (21967700142).

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

21948309618 is a wasteful number, since it uses less digits than its factorization.

21948309618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1615881.

The product of its (nonzero) digits is 746496, while the sum is 51.

The spelling of 21948309618 in words is "twenty-one billion, nine hundred forty-eight million, three hundred nine thousand, six hundred eighteen".