65634649920 has 1344 divisors, whose sum is σ = 291888769536. Its totient is φ = 13695713280.

The previous prime is 65634649897. The next prime is 65634649931. The reversal of 65634649920 is 2994643656.

It is a tau number, because it is divible by the number of its divisors (1344).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 379390954 + ... + 379391126.

It is an arithmetic number, because the mean of its divisors is an integer number (217179144).

Almost surely, 2^65634649920 is an apocalyptic number.

65634649920 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 65634649920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (145944384768).

65634649920 is an abundant number, since it is smaller than the sum of its proper divisors (226254119616).

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

65634649920 is a wasteful number, since it uses less digits than its factorization.

65634649920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 270 (or 248 counting only the distinct ones).

The product of its (nonzero) digits is 8398080, while the sum is 54.

It can be divided in two parts, 656346 and 49920, that added together give a triangular number (706266 = T₁₁₈₈).

The spelling of 65634649920 in words is "sixty-five billion, six hundred thirty-four million, six hundred forty-nine thousand, nine hundred twenty".