1720940213923 has 16 divisors (see below), whose sum is σ = 1978024112064. Its totient is φ = 1466668183680.

The previous prime is 1720940213917. The next prime is 1720940213959. The reversal of 1720940213923 is 3293120490271.

It is a de Polignac number, because none of the positive numbers 2^k-1720940213923 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1720940213923.

It is not an unprimeable number, because it can be changed into a prime (1720940213983) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6815361 + ... + 7063357.

It is an arithmetic number, because the mean of its divisors is an integer number (123626507004).

Almost surely, 2^{1720940213923} is an apocalyptic number.

1720940213923 is a deficient number, since it is larger than the sum of its proper divisors (257083898141).

1720940213923 is a wasteful number, since it uses less digits than its factorization.

1720940213923 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 253662.

The product of its (nonzero) digits is 163296, while the sum is 43.

The spelling of 1720940213923 in words is "one trillion, seven hundred twenty billion, nine hundred forty million, two hundred thirteen thousand, nine hundred twenty-three".