2001980521 has 4 divisors (see below), whose sum is σ = 2003181700. Its totient is φ = 2000779344.

The previous prime is 2001980483. The next prime is 2001980567. The reversal of 2001980521 is 1250891002.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1250891002 = 2 ⋅625445501.

It can be written as a sum of positive squares in 2 ways, for example, as 1704038400 + 297942121 = 41280^2 + 17261^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2001980521 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2001980521.

It is not an unprimeable number, because it can be changed into a prime (2001980621) 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, 598086 + ... + 601423.

It is an arithmetic number, because the mean of its divisors is an integer number (500795425).

Almost surely, 2^2001980521 is an apocalyptic number.

It is an amenable number.

2001980521 is a deficient number, since it is larger than the sum of its proper divisors (1201179).

2001980521 is a wasteful number, since it uses less digits than its factorization.

2001980521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1201178.

The product of its (nonzero) digits is 1440, while the sum is 28.

The square root of 2001980521 is about 44743.4969688334. The cubic root of 2001980521 is about 1260.3367960423.

The spelling of 2001980521 in words is "two billion, one million, nine hundred eighty thousand, five hundred twenty-one".