1298789640 has 320 divisors, whose sum is σ = 4597148160. Its totient is φ = 328458240.

The previous prime is 1298789633. The next prime is 1298789663. The reversal of 1298789640 is 469878921.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 6729384 + ... + 6729576.

It is an arithmetic number, because the mean of its divisors is an integer number (14366088).

Almost surely, 2^1298789640 is an apocalyptic number.

1298789640 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 1298789640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2298574080).

1298789640 is an abundant number, since it is smaller than the sum of its proper divisors (3298358520).

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

1298789640 is a wasteful number, since it uses less digits than its factorization.

1298789640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 314 (or 301 counting only the distinct ones).

The product of its (nonzero) digits is 1741824, while the sum is 54.

The square root of 1298789640 is about 36038.7241727562. The cubic root of 1298789640 is about 1091.0540655057.

The spelling of 1298789640 in words is "one billion, two hundred ninety-eight million, seven hundred eighty-nine thousand, six hundred forty".