1720704993021 has 36 divisors (see below), whose sum is σ = 2892505403424. Its totient is φ = 982833944400.

The previous prime is 1720704993011. The next prime is 1720704993023. The reversal of 1720704993021 is 1203994070271.

1720704993021 is a `hidden beast` number, since 1 + 72 + 0 + 70 + 499 + 3 + 0 + 21 = 666.

It is not a de Polignac number, because 1720704993021 - 2¹⁷ = 1720704861949 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1720704993023) by changing a digit.

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 35 ways as a sum of consecutive naturals, for example, 174966 + ... + 1863336.

Almost surely, 2^{1720704993021} is an apocalyptic number.

It is an amenable number.

1720704993021 is a deficient number, since it is larger than the sum of its proper divisors (1171800410403).

1720704993021 is a wasteful number, since it uses less digits than its factorization.

1720704993021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1690702 (or 1690692 counting only the distinct ones).

The product of its (nonzero) digits is 190512, while the sum is 45.

The spelling of 1720704993021 in words is "one trillion, seven hundred twenty billion, seven hundred four million, nine hundred ninety-three thousand, twenty-one".