1621625663440 has 40 divisors (see below), whose sum is σ = 3806884343808. Its totient is φ = 642352686720.

The previous prime is 1621625663423. The next prime is 1621625663461. The reversal of 1621625663440 is 443665261261.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 98391376 + ... + 98407855.

Almost surely, 2^{1621625663440} is an apocalyptic number.

1621625663440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1621625663440 is an abundant number, since it is smaller than the sum of its proper divisors (2185258680368).

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

1621625663440 is a wasteful number, since it uses less digits than its factorization.

1621625663440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 196799347 (or 196799341 counting only the distinct ones).

The product of its (nonzero) digits is 1244160, while the sum is 46.

The spelling of 1621625663440 in words is "one trillion, six hundred twenty-one billion, six hundred twenty-five million, six hundred sixty-three thousand, four hundred forty".