1721428556 has 12 divisors (see below), whose sum is σ = 3035497080. Its totient is φ = 854143680.

The previous prime is 1721428507. The next prime is 1721428559. The reversal of 1721428556 is 6558241271.

It is a hoax number, since the sum of its digits (41) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (1721428559) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1642061 + ... + 1643108.

It is an arithmetic number, because the mean of its divisors is an integer number (252958090).

Almost surely, 2^1721428556 is an apocalyptic number.

It is an amenable number.

1721428556 is a deficient number, since it is larger than the sum of its proper divisors (1314068524).

1721428556 is a wasteful number, since it uses less digits than its factorization.

1721428556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3285304 (or 3285302 counting only the distinct ones).

The product of its digits is 134400, while the sum is 41.

The square root of 1721428556 is about 41490.1019039481. The cubic root of 1721428556 is about 1198.4769000307.

The spelling of 1721428556 in words is "one billion, seven hundred twenty-one million, four hundred twenty-eight thousand, five hundred fifty-six".