1647628042 has 4 divisors (see below), whose sum is σ = 2471442066. Its totient is φ = 823814020.

The previous prime is 1647627991. The next prime is 1647628043. The reversal of 1647628042 is 2408267461.

It is a happy number.

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., 1583323681 + 64304361 = 39791^2 + 8019^2 .

It is a super-4 number, since 4×1647628042⁴ (a number of 38 digits) contains 4444 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1647627986 and 1647628004.

It is not an unprimeable number, because it can be changed into a prime (1647628043) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 411907009 + ... + 411907012.

Almost surely, 2^1647628042 is an apocalyptic number.

1647628042 is a deficient number, since it is larger than the sum of its proper divisors (823814024).

1647628042 is an equidigital number, since it uses as much as digits as its factorization.

1647628042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 823814023.

The product of its (nonzero) digits is 129024, while the sum is 40.

The square root of 1647628042 is about 40590.9847379932. The cubic root of 1647628042 is about 1181.0992442678.

The spelling of 1647628042 in words is "one billion, six hundred forty-seven million, six hundred twenty-eight thousand, forty-two".