21165557150 has 12 divisors (see below), whose sum is σ = 39367936392. Its totient is φ = 8466222840.

The previous prime is 21165557111. The next prime is 21165557159. The reversal of 21165557150 is 5175556112.

It is a happy number.

It is a super-2 number, since 2×21165557150² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21165557159) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 211655522 + ... + 211655621.

It is an arithmetic number, because the mean of its divisors is an integer number (3280661366).

Almost surely, 2^21165557150 is an apocalyptic number.

21165557150 is a deficient number, since it is larger than the sum of its proper divisors (18202379242).

21165557150 is a wasteful number, since it uses less digits than its factorization.

21165557150 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 423311155 (or 423311150 counting only the distinct ones).

The product of its (nonzero) digits is 52500, while the sum is 38.

The spelling of 21165557150 in words is "twenty-one billion, one hundred sixty-five million, five hundred fifty-seven thousand, one hundred fifty".