1406390138 has 4 divisors (see below), whose sum is σ = 2109585210. Its totient is φ = 703195068.

The previous prime is 1406390137. The next prime is 1406390149. The reversal of 1406390138 is 8310936041.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 989291209 + 417098929 = 31453^2 + 20423^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1406390098 and 1406390107.

It is not an unprimeable number, because it can be changed into a prime (1406390137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 351597533 + ... + 351597536.

Almost surely, 2^1406390138 is an apocalyptic number.

1406390138 is a deficient number, since it is larger than the sum of its proper divisors (703195072).

1406390138 is an equidigital number, since it uses as much as digits as its factorization.

1406390138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 703195071.

The product of its (nonzero) digits is 15552, while the sum is 35.

The square root of 1406390138 is about 37501.8684601181. The cubic root of 1406390138 is about 1120.3884011127.

The spelling of 1406390138 in words is "one billion, four hundred six million, three hundred ninety thousand, one hundred thirty-eight".