621444531445 has 4 divisors (see below), whose sum is σ = 745733437740. Its totient is φ = 497155625152.

The previous prime is 621444531427. The next prime is 621444531457. The reversal of 621444531445 is 544135444126.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 544135444126 = 2 ⋅272067722063.

It can be written as a sum of positive squares in 2 ways, for example, as 328955014116 + 292489517329 = 573546^2 + 540823^2 .

It is a cyclic number.

It is not a de Polignac number, because 621444531445 - 2⁷ = 621444531317 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 62144453140 + ... + 62144453149.

It is an arithmetic number, because the mean of its divisors is an integer number (186433359435).

Almost surely, 2^621444531445 is an apocalyptic number.

It is an amenable number.

621444531445 is a deficient number, since it is larger than the sum of its proper divisors (124288906295).

621444531445 is a wasteful number, since it uses less digits than its factorization.

621444531445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124288906294.

The product of its digits is 921600, while the sum is 43.

The spelling of 621444531445 in words is "six hundred twenty-one billion, four hundred forty-four million, five hundred thirty-one thousand, four hundred forty-five".