21250225666542 has 64 divisors (see below), whose sum is σ = 44869396320000. Its totient is φ = 6690789070848.

The previous prime is 21250225666531. The next prime is 21250225666543. The reversal of 21250225666542 is 24566652205212.

It is a junction number, because it is equal to n+sod(n) for n = 21250225666491 and 21250225666500.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21250225666543) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 858131853 + ... + 858156615.

It is an arithmetic number, because the mean of its divisors is an integer number (701084317500).

Almost surely, 2^{21250225666542} is an apocalyptic number.

21250225666542 is an abundant number, since it is smaller than the sum of its proper divisors (23619170653458).

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

21250225666542 is a wasteful number, since it uses less digits than its factorization.

21250225666542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46705.

The product of its (nonzero) digits is 3456000, while the sum is 48.

The spelling of 21250225666542 in words is "twenty-one trillion, two hundred fifty billion, two hundred twenty-five million, six hundred sixty-six thousand, five hundred forty-two".