21978694832 has 10 divisors (see below), whose sum is σ = 42583721268. Its totient is φ = 10989347408.

The previous prime is 21978694813. The next prime is 21978694879. The reversal of 21978694832 is 23849687912.

It is a happy number.

It is a super-3 number, since 3×21978694832³ (a number of 32 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 686834198 + ... + 686834229.

Almost surely, 2^21978694832 is an apocalyptic number.

It is an amenable number.

21978694832 is a deficient number, since it is larger than the sum of its proper divisors (20605026436).

21978694832 is a wasteful number, since it uses less digits than its factorization.

21978694832 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1373668435 (or 1373668429 counting only the distinct ones).

The product of its digits is 10450944, while the sum is 59.

The spelling of 21978694832 in words is "twenty-one billion, nine hundred seventy-eight million, six hundred ninety-four thousand, eight hundred thirty-two".