521980649 has 4 divisors (see below), whose sum is σ = 523485264. Its totient is φ = 520476036.

The previous prime is 521980643. The next prime is 521980663. The reversal of 521980649 is 946089125.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-521980649 is a prime.

It is a super-2 number, since 2×521980649² = 544927595860922402, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (521980643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 751787 + ... + 752480.

It is an arithmetic number, because the mean of its divisors is an integer number (130871316).

Almost surely, 2^521980649 is an apocalyptic number.

It is an amenable number.

521980649 is a deficient number, since it is larger than the sum of its proper divisors (1504615).

521980649 is a wasteful number, since it uses less digits than its factorization.

521980649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1504614.

The product of its (nonzero) digits is 155520, while the sum is 44.

The square root of 521980649 is about 22846.8958285365. The cubic root of 521980649 is about 805.1648384840.

The spelling of 521980649 in words is "five hundred twenty-one million, nine hundred eighty thousand, six hundred forty-nine".