78420090554 has 16 divisors (see below), whose sum is σ = 126685120128. Its totient is φ = 36192027312.

The previous prime is 78420090521. The next prime is 78420090569. The reversal of 78420090554 is 45509002487.

It is a happy number.

It is a super-2 number, since 2×78420090554² (a number of 23 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 526859 + ... + 659105.

It is an arithmetic number, because the mean of its divisors is an integer number (7917820008).

Almost surely, 2^78420090554 is an apocalyptic number.

78420090554 is a deficient number, since it is larger than the sum of its proper divisors (48265029574).

78420090554 is a wasteful number, since it uses less digits than its factorization.

78420090554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155069.

The product of its (nonzero) digits is 403200, while the sum is 44.

The spelling of 78420090554 in words is "seventy-eight billion, four hundred twenty million, ninety thousand, five hundred fifty-four".