16021451731778 has 4 divisors (see below), whose sum is σ = 24032177597670. Its totient is φ = 8010725865888.

The previous prime is 16021451731721. The next prime is 16021451731783. The reversal of 16021451731778 is 87713715412061.

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

It can be written as a sum of positive squares in only one way, i.e., 15992664840889 + 28786890889 = 3999083^2 + 169667^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4005362932943 + ... + 4005362932946.

Almost surely, 2^{16021451731778} is an apocalyptic number.

16021451731778 is a deficient number, since it is larger than the sum of its proper divisors (8010725865892).

16021451731778 is an equidigital number, since it uses as much as digits as its factorization.

16021451731778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8010725865891.

The product of its (nonzero) digits is 1975680, while the sum is 53.

The spelling of 16021451731778 in words is "sixteen trillion, twenty-one billion, four hundred fifty-one million, seven hundred thirty-one thousand, seven hundred seventy-eight".