247421780 has 48 divisors (see below), whose sum is σ = 531210960. Its totient is φ = 96780288.

The previous prime is 247421777. The next prime is 247421789. The reversal of 247421780 is 87124742.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 1684804 + 245736976 = 1298^2 + 15676^2 .

It is a super-2 number, since 2×247421780² = 122435074436736800, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 247421780.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (247421789) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 171944 + ... + 173376.

It is an arithmetic number, because the mean of its divisors is an integer number (11066895).

Almost surely, 2^247421780 is an apocalyptic number.

247421780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

247421780 is an abundant number, since it is smaller than the sum of its proper divisors (283789180).

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

247421780 is a wasteful number, since it uses less digits than its factorization.

247421780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1628 (or 1626 counting only the distinct ones).

The product of its (nonzero) digits is 25088, while the sum is 35.

The square root of 247421780 is about 15729.6465313115. The cubic root of 247421780 is about 627.7874684825.

The spelling of 247421780 in words is "two hundred forty-seven million, four hundred twenty-one thousand, seven hundred eighty".