1721090813 has 16 divisors (see below), whose sum is σ = 1957475520. Its totient is φ = 1500114816.

The previous prime is 1721090807. The next prime is 1721090821. The reversal of 1721090813 is 3180901271.

It is a cyclic number.

It is not a de Polignac number, because 1721090813 - 2²² = 1716896509 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1721090813.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1721090843) 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, 64481 + ... + 87177.

It is an arithmetic number, because the mean of its divisors is an integer number (122342220).

Almost surely, 2^1721090813 is an apocalyptic number.

1721090813 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

1721090813 is a deficient number, since it is larger than the sum of its proper divisors (236384707).

1721090813 is a wasteful number, since it uses less digits than its factorization.

1721090813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23036.

The product of its (nonzero) digits is 3024, while the sum is 32.

The square root of 1721090813 is about 41486.0315407487. The cubic root of 1721090813 is about 1198.3985148125.

The spelling of 1721090813 in words is "one billion, seven hundred twenty-one million, ninety thousand, eight hundred thirteen".