64423540 has 48 divisors (see below), whose sum is σ = 144925200. Its totient is φ = 23969792.

The previous prime is 64423507. The next prime is 64423553. The reversal of 64423540 is 4532446.

It can be written as a sum of positive squares in 8 ways, for example, as 3020644 + 61402896 = 1738^2 + 7836^2 .

It is a super-2 number, since 2×64423540² = 8300785012263200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 64423499 and 64423508.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29196 + ... + 31324.

It is an arithmetic number, because the mean of its divisors is an integer number (3019275).

Almost surely, 2^64423540 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 64423540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (72462600).

64423540 is an abundant number, since it is smaller than the sum of its proper divisors (80501660).

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

64423540 is a wasteful number, since it uses less digits than its factorization.

64423540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2244 (or 2242 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 28.

The square root of 64423540 is about 8026.4275988761. The cubic root of 64423540 is about 400.8804356608.

Adding to 64423540 its reverse (4532446), we get a palindrome (68955986).

The spelling of 64423540 in words is "sixty-four million, four hundred twenty-three thousand, five hundred forty".