78280442 has 4 divisors (see below), whose sum is σ = 117420666. Its totient is φ = 39140220.

The previous prime is 78280441. The next prime is 78280457. The reversal of 78280442 is 24408287.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24408287 = 1103 ⋅22129.

It can be written as a sum of positive squares in only one way, i.e., 75359761 + 2920681 = 8681^2 + 1709^2 .

It is a super-2 number, since 2×78280442² = 12255655199430728, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78280441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19570109 + ... + 19570112.

Almost surely, 2^78280442 is an apocalyptic number.

78280442 is a deficient number, since it is larger than the sum of its proper divisors (39140224).

78280442 is a wasteful number, since it uses less digits than its factorization.

78280442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39140223.

The product of its (nonzero) digits is 28672, while the sum is 35.

The square root of 78280442 is about 8847.6235227320. The cubic root of 78280442 is about 427.7773210592. Note that the first 3 decimals are identical.

The spelling of 78280442 in words is "seventy-eight million, two hundred eighty thousand, four hundred forty-two".