1257220240 has 40 divisors (see below), whose sum is σ = 2991022848. Its totient is φ = 491191680.

The previous prime is 1257220229. The next prime is 1257220243. The reversal of 1257220240 is 420227521.

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (1257220243) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 179296 + ... + 186175.

Almost surely, 2^1257220240 is an apocalyptic number.

1257220240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1257220240 is an abundant number, since it is smaller than the sum of its proper divisors (1733802608).

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

1257220240 is a wasteful number, since it uses less digits than its factorization.

1257220240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 365527 (or 365521 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 25.

The square root of 1257220240 is about 35457.3016457824. The cubic root of 1257220240 is about 1079.2874357736.

Adding to 1257220240 its reverse (420227521), we get a palindrome (1677447761).

The spelling of 1257220240 in words is "one billion, two hundred fifty-seven million, two hundred twenty thousand, two hundred forty".