78217272 has 192 divisors, whose sum is σ = 265248000. Its totient is φ = 20915712.

The previous prime is 78217267. The next prime is 78217277. The reversal of 78217272 is 27271287.

It is an interprime number because it is at equal distance from previous prime (78217267) and next prime (78217277).

It is a super-2 number, since 2×78217272² = 12235883278243968, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78217277) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 436879 + ... + 437057.

It is an arithmetic number, because the mean of its divisors is an integer number (1381500).

Almost surely, 2^78217272 is an apocalyptic number.

78217272 is a gapful number since it is divisible by the number (72) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78217272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (132624000).

78217272 is an abundant number, since it is smaller than the sum of its proper divisors (187030728).

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

78217272 is a wasteful number, since it uses less digits than its factorization.

78217272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 235 (or 208 counting only the distinct ones).

The product of its digits is 21952, while the sum is 36.

The square root of 78217272 is about 8844.0529170737. The cubic root of 78217272 is about 427.6622222138.

The spelling of 78217272 in words is "seventy-eight million, two hundred seventeen thousand, two hundred seventy-two".