78211980 has 432 divisors, whose sum is σ = 325328640. Its totient is φ = 15396480.

The previous prime is 78211963. The next prime is 78211997. The reversal of 78211980 is 8911287.

It is an interprime number because it is at equal distance from previous prime (78211963) and next prime (78211997).

It is a super-2 number, since 2×78211980² = 12234227631040800, which contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 4116411 + ... + 4116429.

Almost surely, 2^78211980 is an apocalyptic number.

78211980 is a gapful number since it is divisible by the number (70) 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 78211980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (162664320).

78211980 is an abundant number, since it is smaller than the sum of its proper divisors (247116660).

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

78211980 is a wasteful number, since it uses less digits than its factorization.

78211980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72 (or 47 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 36.

The square root of 78211980 is about 8843.7537279144. The cubic root of 78211980 is about 427.6525771169.

It can be divided in two parts, 7821 and 1980, that added together give a square (9801 = 99²).

The spelling of 78211980 in words is "seventy-eight million, two hundred eleven thousand, nine hundred eighty".