1620621616766 has 4 divisors (see below), whose sum is σ = 2430932425152. Its totient is φ = 810310808382.

The previous prime is 1620621616727. The next prime is 1620621616781. The reversal of 1620621616766 is 6676161260261.

It is a semiprime because it is the product of two primes.

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 as a sum of consecutive naturals, namely, 405155404190 + ... + 405155404193.

It is an arithmetic number, because the mean of its divisors is an integer number (607733106288).

Almost surely, 2^{1620621616766} is an apocalyptic number.

1620621616766 is a deficient number, since it is larger than the sum of its proper divisors (810310808386).

1620621616766 is an equidigital number, since it uses as much as digits as its factorization.

1620621616766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 810310808385.

The product of its (nonzero) digits is 1306368, while the sum is 50.

The spelling of 1620621616766 in words is "one trillion, six hundred twenty billion, six hundred twenty-one million, six hundred sixteen thousand, seven hundred sixty-six".