64121440 has 24 divisors (see below), whose sum is σ = 151487280. Its totient is φ = 25648512.

The previous prime is 64121437. The next prime is 64121441. The reversal of 64121440 is 4412146.

It is a super-2 number, since 2×64121440² = 8223118135347200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64121441) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 200220 + ... + 200539.

It is an arithmetic number, because the mean of its divisors is an integer number (6311970).

Almost surely, 2^64121440 is an apocalyptic number.

It is an amenable number.

64121440 is an abundant number, since it is smaller than the sum of its proper divisors (87365840).

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

64121440 is a wasteful number, since it uses less digits than its factorization.

64121440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 400774 (or 400766 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 64121440 is about 8007.5864029057. The cubic root of 64121440 is about 400.2528401460.

Adding to 64121440 its reverse (4412146), we get a palindrome (68533586).

The spelling of 64121440 in words is "sixty-four million, one hundred twenty-one thousand, four hundred forty".