65989980 has 144 divisors (see below), whose sum is σ = 231888384. Its totient is φ = 14878080.

The previous prime is 65989969. The next prime is 65989991. The reversal of 65989980 is 8998956.

65989980 = T₁₀₄ + T₁₀₅ + ... + T₇₃₄.

It is an interprime number because it is at equal distance from previous prime (65989969) and next prime (65989991).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 104265 + ... + 104895.

It is an arithmetic number, because the mean of its divisors is an integer number (1610336).

Almost surely, 2^65989980 is an apocalyptic number.

65989980 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 65989980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (115944192).

65989980 is an abundant number, since it is smaller than the sum of its proper divisors (165898404).

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

65989980 is a wasteful number, since it uses less digits than its factorization.

65989980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 736 (or 731 counting only the distinct ones).

The product of its (nonzero) digits is 1399680, while the sum is 54.

The square root of 65989980 is about 8123.4216928583. The cubic root of 65989980 is about 404.1035499034.

The spelling of 65989980 in words is "sixty-five million, nine hundred eighty-nine thousand, nine hundred eighty".