78121010 has 32 divisors (see below), whose sum is σ = 154377792. Its totient is φ = 28226880.

The previous prime is 78121009. The next prime is 78121013. The reversal of 78121010 is 1012187.

It is a super-2 number, since 2×78121010² = 12205784406840200, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is not an unprimeable number, because it can be changed into a prime (78121013) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15752 + ... + 20108.

It is an arithmetic number, because the mean of its divisors is an integer number (4824306).

Almost surely, 2^78121010 is an apocalyptic number.

78121010 is a deficient number, since it is larger than the sum of its proper divisors (76256782).

78121010 is a wasteful number, since it uses less digits than its factorization.

78121010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4538.

The product of its (nonzero) digits is 112, while the sum is 20.

The square root of 78121010 is about 8838.6090534654. The cubic root of 78121010 is about 427.4867088876.

Adding to 78121010 its reverse (1012187), we get a palindrome (79133197).

The spelling of 78121010 in words is "seventy-eight million, one hundred twenty-one thousand, ten".