78221052 has 180 divisors, whose sum is σ = 256844280. Its totient is φ = 20575296.

The previous prime is 78221047. The next prime is 78221053. The reversal of 78221052 is 25012287.

It is a super-2 number, since 2×78221052² = 12237065951973408, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78221053) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 206199 + ... + 206577.

Almost surely, 2^78221052 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78221052, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128422140).

78221052 is an abundant number, since it is smaller than the sum of its proper divisors (178623228).

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

78221052 is a wasteful number, since it uses less digits than its factorization.

78221052 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 422 (or 404 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 78221052 is about 8844.2666174194. The cubic root of 78221052 is about 427.6691113025.

The spelling of 78221052 in words is "seventy-eight million, two hundred twenty-one thousand, fifty-two".