1290987720 has 480 divisors, whose sum is σ = 4953425400. Its totient is φ = 301086720.

The previous prime is 1290987707. The next prime is 1290987721. The reversal of 1290987720 is 277890921.

It can be written as a sum of positive squares in 4 ways, for example, as 1093360356 + 197627364 = 33066^2 + 14058^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (1290987721) by changing a digit.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 14505436 + ... + 14505524.

Almost surely, 2^1290987720 is an apocalyptic number.

1290987720 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 1290987720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2476712700).

1290987720 is an abundant number, since it is smaller than the sum of its proper divisors (3662437680).

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

1290987720 is a wasteful number, since it uses less digits than its factorization.

1290987720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171 (or 147 counting only the distinct ones).

The product of its (nonzero) digits is 127008, while the sum is 45.

The square root of 1290987720 is about 35930.3175605226. The cubic root of 1290987720 is about 1088.8649970385.

The spelling of 1290987720 in words is "one billion, two hundred ninety million, nine hundred eighty-seven thousand, seven hundred twenty".