641978089 has 16 divisors (see below), whose sum is σ = 697669632. Its totient is φ = 588365568.

The previous prime is 641978087. The next prime is 641978111. The reversal of 641978089 is 980879146.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 641978089 - 2¹ = 641978087 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (641978087) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 278827 + ... + 281119.

It is an arithmetic number, because the mean of its divisors is an integer number (43604352).

Almost surely, 2^641978089 is an apocalyptic number.

It is an amenable number.

641978089 is a deficient number, since it is larger than the sum of its proper divisors (55691543).

641978089 is a wasteful number, since it uses less digits than its factorization.

641978089 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2736.

The product of its (nonzero) digits is 870912, while the sum is 52.

The square root of 641978089 is about 25337.2865358546. The cubic root of 641978089 is about 862.6608094474.

The spelling of 641978089 in words is "six hundred forty-one million, nine hundred seventy-eight thousand, eighty-nine".