247440 has 40 divisors (see below), whose sum is σ = 767808. Its totient is φ = 65920.

The previous prime is 247439. The next prime is 247451. The reversal of 247440 is 44742.

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

It is a super-2 number, since 2×247440² = 122453107200, which contains 22 as substring.

It is a Smith number, since the sum of its digits (21) coincides with the sum of the digits of its prime factors.

It is a nialpdrome in base 8.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 276 + ... + 755.

2²⁴⁷⁴⁴⁰ is an apocalyptic number.

247440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

247440 is an abundant number, since it is smaller than the sum of its proper divisors (520368).

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

247440 is a wasteful number, since it uses less digits than its factorization.

247440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1047 (or 1041 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 21.

The square root of 247440 is about 497.4334126293. The cubic root of 247440 is about 62.7802878076.

The spelling of 247440 in words is "two hundred forty-seven thousand, four hundred forty", and thus it is an iban number.