1721987020 has 24 divisors (see below), whose sum is σ = 3894340464. Its totient is φ = 635810496.

The previous prime is 1721987017. The next prime is 1721987053. The reversal of 1721987020 is 207891271.

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3311254 + ... + 3311773.

It is an arithmetic number, because the mean of its divisors is an integer number (162264186).

Almost surely, 2^1721987020 is an apocalyptic number.

1721987020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1721987020 is an abundant number, since it is smaller than the sum of its proper divisors (2172353444).

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

1721987020 is a wasteful number, since it uses less digits than its factorization.

1721987020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6623049 (or 6623047 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 37.

The square root of 1721987020 is about 41496.8314453044. The cubic root of 1721987020 is about 1198.6064888802.

It can be divided in two parts, 172 and 1987020, that multiplied together give a triangular number (341767440 = T₂₆₁₄₄).

The spelling of 1721987020 in words is "one billion, seven hundred twenty-one million, nine hundred eighty-seven thousand, twenty".