64688561420 has 96 divisors (see below), whose sum is σ = 158769171456. Its totient is φ = 21681043200.

The previous prime is 64688561417. The next prime is 64688561423. The reversal of 64688561420 is 2416588646.

It is an interprime number because it is at equal distance from previous prime (64688561417) and next prime (64688561423).

It is a super-2 number, since 2×64688561420² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (64688561423) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1368785 + ... + 1415255.

It is an arithmetic number, because the mean of its divisors is an integer number (1653845536).

Almost surely, 2^64688561420 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64688561420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (79384585728).

64688561420 is an abundant number, since it is smaller than the sum of its proper divisors (94080610036).

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

64688561420 is a wasteful number, since it uses less digits than its factorization.

64688561420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46711 (or 46709 counting only the distinct ones).

The product of its (nonzero) digits is 2211840, while the sum is 50.

The spelling of 64688561420 in words is "sixty-four billion, six hundred eighty-eight million, five hundred sixty-one thousand, four hundred twenty".