1721351020 has 12 divisors (see below), whose sum is σ = 3614837184. Its totient is φ = 688540400.

The previous prime is 1721351003. The next prime is 1721351029. The reversal of 1721351020 is 201531271.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 1721350982 and 1721351000.

It is not an unprimeable number, because it can be changed into a prime (1721351029) 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, 43033756 + ... + 43033795.

It is an arithmetic number, because the mean of its divisors is an integer number (301236432).

Almost surely, 2^1721351020 is an apocalyptic number.

1721351020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1721351020 is an abundant number, since it is smaller than the sum of its proper divisors (1893486164).

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

1721351020 is a wasteful number, since it uses less digits than its factorization.

1721351020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86067560 (or 86067558 counting only the distinct ones).

The product of its (nonzero) digits is 420, while the sum is 22.

The square root of 1721351020 is about 41489.1675018914. The cubic root of 1721351020 is about 1198.4589059641.

Adding to 1721351020 its reverse (201531271), we get a palindrome (1922882291).

The spelling of 1721351020 in words is "one billion, seven hundred twenty-one million, three hundred fifty-one thousand, twenty".