139409028 has 36 divisors (see below), whose sum is σ = 384432048. Its totient is φ = 42245040.

The previous prime is 139408991. The next prime is 139409029. The reversal of 139409028 is 820904931.

It is a tau number, because it is divible by the number of its divisors (36).

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

It is a junction number, because it is equal to n+sod(n) for n = 139408983 and 139409001.

It is not an unprimeable number, because it can be changed into a prime (139409029) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 175626 + ... + 176417.

It is an arithmetic number, because the mean of its divisors is an integer number (10678668).

Almost surely, 2^139409028 is an apocalyptic number.

139409028 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

139409028 is an abundant number, since it is smaller than the sum of its proper divisors (245023020).

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

139409028 is a wasteful number, since it uses less digits than its factorization.

139409028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 352064 (or 352059 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 139409028 is about 11807.1600310998. The cubic root of 139409028 is about 518.5177562425.

The spelling of 139409028 in words is "one hundred thirty-nine million, four hundred nine thousand, twenty-eight".