1001720816 has 20 divisors (see below), whose sum is σ = 1941712032. Its totient is φ = 500633856.

The previous prime is 1001720803. The next prime is 1001720849. The reversal of 1001720816 is 6180271001.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25721 + ... + 51623.

Almost surely, 2^1001720816 is an apocalyptic number.

1001720816 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1001720816 is a deficient number, since it is larger than the sum of its proper divisors (939991216).

1001720816 is a wasteful number, since it uses less digits than its factorization.

1001720816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28328 (or 28322 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 26.

The square root of 1001720816 is about 31649.9733965133. The cubic root of 1001720816 is about 1000.5732766244.

Adding to 1001720816 its reverse (6180271001), we get a palindrome (7181991817).

The spelling of 1001720816 in words is "one billion, one million, seven hundred twenty thousand, eight hundred sixteen".