621521213526464 has 28 divisors (see below), whose sum is σ = 1233440681869608. Its totient is φ = 310733010220800.

The previous prime is 621521213526463. The next prime is 621521213526481. The reversal of 621521213526464 is 464625312125126.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621521213526463) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 430469642 + ... + 431911049.

Almost surely, 2^{621521213526464} is an apocalyptic number.

621521213526464 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

621521213526464 is a deficient number, since it is larger than the sum of its proper divisors (611919468343144).

621521213526464 is a wasteful number, since it uses less digits than its factorization.

621521213526464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 862391964 (or 862391954 counting only the distinct ones).

The product of its digits is 4147200, while the sum is 50.

The spelling of 621521213526464 in words is "six hundred twenty-one trillion, five hundred twenty-one billion, two hundred thirteen million, five hundred twenty-six thousand, four hundred sixty-four".