1256909490 has 48 divisors (see below), whose sum is σ = 3273962328. Its totient is φ = 334560768.

The previous prime is 1256909471. The next prime is 1256909491. The reversal of 1256909490 is 949096521.

It can be written as a sum of positive squares in 4 ways, for example, as 663938289 + 592971201 = 25767^2 + 24351^2 .

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

It is an alternating number because its digits alternate between odd and even.

It is not an unprimeable number, because it can be changed into a prime (1256909491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 37594 + ... + 62666.

Almost surely, 2^1256909490 is an apocalyptic number.

1256909490 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1256909490 is an abundant number, since it is smaller than the sum of its proper divisors (2017052838).

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

1256909490 is a wasteful number, since it uses less digits than its factorization.

1256909490 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25643 (or 25640 counting only the distinct ones).

The product of its (nonzero) digits is 174960, while the sum is 45.

The square root of 1256909490 is about 35452.9193438284. The cubic root of 1256909490 is about 1079.1985051321.

The spelling of 1256909490 in words is "one billion, two hundred fifty-six million, nine hundred nine thousand, four hundred ninety".