1721916 has 36 divisors (see below), whose sum is σ = 4975152. Its totient is φ = 491904.

The previous prime is 1721911. The next prime is 1721921. The reversal of 1721916 is 6191271.

It is an interprime number because it is at equal distance from previous prime (1721911) and next prime (1721921).

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×1721916² = 5929989422112, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 1721916.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1721911) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3165 + ... + 3668.

2^1721916 is an apocalyptic number.

It is an amenable number.

1721916 is an abundant number, since it is smaller than the sum of its proper divisors (3253236).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1721916 is a wasteful number, since it uses less digits than its factorization.

1721916 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6850 (or 6845 counting only the distinct ones).

The product of its digits is 756, while the sum is 27.

The square root of 1721916 is about 1312.2179696986. The cubic root of 1721916 is about 119.8590010590.

The spelling of 1721916 in words is "one million, seven hundred twenty-one thousand, nine hundred sixteen".