420406138 has 4 divisors (see below), whose sum is σ = 630609210. Its totient is φ = 210203068.

The previous prime is 420406109. The next prime is 420406157. The reversal of 420406138 is 831604024.

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., 355812769 + 64593369 = 18863^2 + 8037^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105101533 + ... + 105101536.

Almost surely, 2^420406138 is an apocalyptic number.

420406138 is a deficient number, since it is larger than the sum of its proper divisors (210203072).

420406138 is a wasteful number, since it uses less digits than its factorization.

420406138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210203071.

The product of its (nonzero) digits is 4608, while the sum is 28.

The square root of 420406138 is about 20503.8078902432. The cubic root of 420406138 is about 749.1285510872.

The spelling of 420406138 in words is "four hundred twenty million, four hundred six thousand, one hundred thirty-eight".