21154668212 has 24 divisors (see below), whose sum is σ = 38268195840. Its totient is φ = 10221850080.

The previous prime is 21154668203. The next prime is 21154668221. The reversal of 21154668212 is 21286645112.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21154668203) and next prime (21154668221).

It is a congruent number.

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, 29483 + ... + 207794.

It is an arithmetic number, because the mean of its divisors is an integer number (1594508160).

Almost surely, 2^21154668212 is an apocalyptic number.

It is an amenable number.

21154668212 is a deficient number, since it is larger than the sum of its proper divisors (17113527628).

21154668212 is a wasteful number, since it uses less digits than its factorization.

21154668212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 238031 (or 238029 counting only the distinct ones).

The product of its digits is 46080, while the sum is 38.

The spelling of 21154668212 in words is "twenty-one billion, one hundred fifty-four million, six hundred sixty-eight thousand, two hundred twelve".