1257809490 has 96 divisors (see below), whose sum is σ = 3757418496. Its totient is φ = 285966720.

The previous prime is 1257809479. The next prime is 1257809513. The reversal of 1257809490 is 949087521.

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

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, 115104 + ... + 125556.

It is an arithmetic number, because the mean of its divisors is an integer number (39139776).

Almost surely, 2^1257809490 is an apocalyptic number.

1257809490 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1257809490, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1878709248).

1257809490 is an abundant number, since it is smaller than the sum of its proper divisors (2499609006).

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

1257809490 is a wasteful number, since it uses less digits than its factorization.

1257809490 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10664 (or 10661 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 45.

The square root of 1257809490 is about 35465.6099623283. The cubic root of 1257809490 is about 1079.4560274992.

The spelling of 1257809490 in words is "one billion, two hundred fifty-seven million, eight hundred nine thousand, four hundred ninety".