1247643684 has 135 divisors (see below), whose sum is σ = 3799690167. Its totient is φ = 344177568.

The previous prime is 1247643673. The next prime is 1247643689. The reversal of 1247643684 is 4863467421.

The square root of 1247643684 is 35322.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 2 ways, for example, as 2965284 + 1244678400 = 1722^2 + 35280^2 .

It is a super-2 number, since 2×1247643684² = 3113229524450183712, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1247643689) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 43022182 + ... + 43022210.

Almost surely, 2^1247643684 is an apocalyptic number.

1247643684 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

1247643684 is the 35322-nd square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1247643684

1247643684 is an abundant number, since it is smaller than the sum of its proper divisors (2552046483).

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

1247643684 is an frugal number, since it uses more digits than its factorization.

1247643684 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140 (or 41 counting only the distinct ones).

The product of its digits is 774144, while the sum is 45.

The cubic root of 1247643684 is about 1076.5400487336.

The spelling of 1247643684 in words is "one billion, two hundred forty-seven million, six hundred forty-three thousand, six hundred eighty-four".