21253544070 has 256 divisors, whose sum is σ = 59617658880. Its totient is φ = 4799692800.

The previous prime is 21253544069. The next prime is 21253544089. The reversal of 21253544070 is 7044535212.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 68339215 + ... + 68339525.

It is an arithmetic number, because the mean of its divisors is an integer number (232881480).

Almost surely, 2^21253544070 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21253544070, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29808829440).

21253544070 is an abundant number, since it is smaller than the sum of its proper divisors (38364114810).

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

21253544070 is a wasteful number, since it uses less digits than its factorization.

21253544070 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 591.

The product of its (nonzero) digits is 33600, while the sum is 33.

The spelling of 21253544070 in words is "twenty-one billion, two hundred fifty-three million, five hundred forty-four thousand, seventy".