1621204512455 has 32 divisors (see below), whose sum is σ = 2159192802816. Its totient is φ = 1158601680000.

The previous prime is 1621204512427. The next prime is 1621204512469. The reversal of 1621204512455 is 5542154021261.

It is not a de Polignac number, because 1621204512455 - 2¹⁰ = 1621204511431 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3224660 + ... + 3693350.

It is an arithmetic number, because the mean of its divisors is an integer number (67474775088).

Almost surely, 2^{1621204512455} is an apocalyptic number.

1621204512455 is a deficient number, since it is larger than the sum of its proper divisors (537988290361).

1621204512455 is a wasteful number, since it uses less digits than its factorization.

1621204512455 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 469799.

The product of its (nonzero) digits is 96000, while the sum is 38.

The spelling of 1621204512455 in words is "one trillion, six hundred twenty-one billion, two hundred four million, five hundred twelve thousand, four hundred fifty-five".