21771049976 has 16 divisors (see below), whose sum is σ = 43960774200. Its totient is φ = 10048176864.

The previous prime is 21771049957. The next prime is 21771050011. The reversal of 21771049976 is 67994017712.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 104668406 + ... + 104668613.

Almost surely, 2^21771049976 is an apocalyptic number.

21771049976 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21771049976 is an abundant number, since it is smaller than the sum of its proper divisors (22189724224).

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

21771049976 is a wasteful number, since it uses less digits than its factorization.

21771049976 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209337038 (or 209337034 counting only the distinct ones).

The product of its (nonzero) digits is 1333584, while the sum is 53.

The spelling of 21771049976 in words is "twenty-one billion, seven hundred seventy-one million, forty-nine thousand, nine hundred seventy-six".