21990146168 has 8 divisors (see below), whose sum is σ = 41231524080. Its totient is φ = 10995073080.

The previous prime is 21990146159. The next prime is 21990146177. The reversal of 21990146168 is 86164109912.

It is an interprime number because it is at equal distance from previous prime (21990146159) and next prime (21990146177).

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1374384128 + ... + 1374384143.

It is an arithmetic number, because the mean of its divisors is an integer number (5153940510).

Almost surely, 2^21990146168 is an apocalyptic number.

It is an amenable number.

21990146168 is a deficient number, since it is larger than the sum of its proper divisors (19241377912).

21990146168 is a wasteful number, since it uses less digits than its factorization.

21990146168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2748768277 (or 2748768273 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 47.

The spelling of 21990146168 in words is "twenty-one billion, nine hundred ninety million, one hundred forty-six thousand, one hundred sixty-eight".