1621525743872 has 72 divisors (see below), whose sum is σ = 3266724937056. Its totient is φ = 803252330496.

The previous prime is 1621525743863. The next prime is 1621525743917. The reversal of 1621525743872 is 2783475251261.

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors.

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, 78297743 + ... + 78318449.

Almost surely, 2^{1621525743872} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1621525743872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1633362468528).

1621525743872 is an abundant number, since it is smaller than the sum of its proper divisors (1645199193184).

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

1621525743872 is a wasteful number, since it uses less digits than its factorization.

1621525743872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23543 (or 23529 counting only the distinct ones).

The product of its digits is 5644800, while the sum is 53.

The spelling of 1621525743872 in words is "one trillion, six hundred twenty-one billion, five hundred twenty-five million, seven hundred forty-three thousand, eight hundred seventy-two".