155478978 has 18 divisors (see below), whose sum is σ = 336985779. Its totient is φ = 51808692.

The previous prime is 155478931. The next prime is 155478979. The reversal of 155478978 is 879874551.

155478978 is a `hidden beast` number, since 1 + 5 + 547 + 8 + 97 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 77739489 + 77739489 = 8817^2 + 8817^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=8817.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (155478979) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 51433 + ... + 54371.

Almost surely, 2^155478978 is an apocalyptic number.

155478978 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

155478978 is an abundant number, since it is smaller than the sum of its proper divisors (181506801).

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

155478978 is an frugal number, since it uses more digits than its factorization.

155478978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5886 (or 2944 counting only the distinct ones).

The product of its digits is 2822400, while the sum is 54.

The square root of 155478978 is about 12469.1209794436. The cubic root of 155478978 is about 537.7212824594.

The spelling of 155478978 in words is "one hundred fifty-five million, four hundred seventy-eight thousand, nine hundred seventy-eight".