1621366664742 has 72 divisors (see below), whose sum is σ = 4064583202680. Its totient is φ = 465464102400.

The previous prime is 1621366664741. The next prime is 1621366664767. The reversal of 1621366664742 is 2474666631261.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1621366664741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 19548859 + ... + 19631622.

Almost surely, 2^{1621366664742} is an apocalyptic number.

1621366664742 is an abundant number, since it is smaller than the sum of its proper divisors (2443216537938).

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

1621366664742 is a wasteful number, since it uses less digits than its factorization.

1621366664742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39180530 (or 39180516 counting only the distinct ones).

The product of its digits is 10450944, while the sum is 54.

The spelling of 1621366664742 in words is "one trillion, six hundred twenty-one billion, three hundred sixty-six million, six hundred sixty-four thousand, seven hundred forty-two".