21212957670 has 16 divisors (see below), whose sum is σ = 50911098480. Its totient is φ = 5656788704.

The previous prime is 21212957627. The next prime is 21212957681. The reversal of 21212957670 is 7675921212.

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, 353549265 + ... + 353549324.

It is an arithmetic number, because the mean of its divisors is an integer number (3181943655).

Almost surely, 2^21212957670 is an apocalyptic number.

21212957670 is an abundant number, since it is smaller than the sum of its proper divisors (29698140810).

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

21212957670 is a wasteful number, since it uses less digits than its factorization.

21212957670 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 707098599.

The product of its (nonzero) digits is 105840, while the sum is 42.

The spelling of 21212957670 in words is "twenty-one billion, two hundred twelve million, nine hundred fifty-seven thousand, six hundred seventy".