78217240 has 32 divisors (see below), whose sum is σ = 176778000. Its totient is φ = 31146624.

The previous prime is 78217231. The next prime is 78217253. The reversal of 78217240 is 4271287.

It is a super-2 number, since 2×78217240² = 12235873266435200, which contains 22 as substring.

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, 4891 + ... + 13429.

Almost surely, 2^78217240 is an apocalyptic number.

It is an amenable number.

78217240 is an abundant number, since it is smaller than the sum of its proper divisors (98560760).

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

78217240 is a wasteful number, since it uses less digits than its factorization.

78217240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8779 (or 8775 counting only the distinct ones).

The product of its (nonzero) digits is 6272, while the sum is 31.

The square root of 78217240 is about 8844.0511079482. The cubic root of 78217240 is about 427.6621638926.

The spelling of 78217240 in words is "seventy-eight million, two hundred seventeen thousand, two hundred forty".