21257154450 has 288 divisors, whose sum is σ = 69552048384. Its totient is φ = 4543672320.

The previous prime is 21257154439. The next prime is 21257154473. The reversal of 21257154450 is 5445175212.

21257154450 is a `hidden beast` number, since 2 + 1 + 2 + 57 + 154 + 450 = 666.

It is a super-3 number, since 3×21257154450³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 8941662 + ... + 8944038.

It is an arithmetic number, because the mean of its divisors is an integer number (241500168).

Almost surely, 2^21257154450 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21257154450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34776024192).

21257154450 is an abundant number, since it is smaller than the sum of its proper divisors (48294893934).

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

21257154450 is a wasteful number, since it uses less digits than its factorization.

21257154450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2586 (or 2578 counting only the distinct ones).

The product of its (nonzero) digits is 56000, while the sum is 36.

The spelling of 21257154450 in words is "twenty-one billion, two hundred fifty-seven million, one hundred fifty-four thousand, four hundred fifty".