64542240 has 288 divisors, whose sum is σ = 265749120. Its totient is φ = 13934592.

The previous prime is 64542227. The next prime is 64542253. The reversal of 64542240 is 4224546.

64542240 = T₅₅ + T₅₆ + ... + T₇₂₈.

It is an interprime number because it is at equal distance from previous prime (64542227) and next prime (64542253).

It is a tau number, because it is divible by the number of its divisors (288).

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, 191352 + ... + 191688.

It is an arithmetic number, because the mean of its divisors is an integer number (922740).

Almost surely, 2^64542240 is an apocalyptic number.

64542240 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 64542240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (132874560).

64542240 is an abundant number, since it is smaller than the sum of its proper divisors (201206880).

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

64542240 is a wasteful number, since it uses less digits than its factorization.

64542240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 384 (or 373 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 27.

The square root of 64542240 is about 8033.8185192348. The cubic root of 64542240 is about 401.1264912323.

Adding to 64542240 its reverse (4224546), we get a palindrome (68766786).

The spelling of 64542240 in words is "sixty-four million, five hundred forty-two thousand, two hundred forty".