1228064640 has 128 divisors (see below), whose sum is σ = 4270389120. Its totient is φ = 297707520.

The previous prime is 1228064611. The next prime is 1228064647. The reversal of 1228064640 is 464608221.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1228064647) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7954 + ... + 50193.

It is an arithmetic number, because the mean of its divisors is an integer number (33362415).

Almost surely, 2^1228064640 is an apocalyptic number.

1228064640 is a gapful number since it is divisible by the number (10) 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 1228064640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2135194560).

1228064640 is an abundant number, since it is smaller than the sum of its proper divisors (3042324480).

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

1228064640 is a wasteful number, since it uses less digits than its factorization.

1228064640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58180 (or 58168 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 33.

The square root of 1228064640 is about 35043.7532236489. The cubic root of 1228064640 is about 1070.8790168132.

The spelling of 1228064640 in words is "one billion, two hundred twenty-eight million, sixty-four thousand, six hundred forty".