1649906971 has 4 divisors (see below), whose sum is σ = 1736744200. Its totient is φ = 1563069744.

The previous prime is 1649906957. The next prime is 1649907019. The reversal of 1649906971 is 1796099461.

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

It is a cyclic number.

It is not a de Polignac number, because 1649906971 - 2¹¹ = 1649904923 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1649906171) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43418586 + ... + 43418623.

It is an arithmetic number, because the mean of its divisors is an integer number (434186050).

Almost surely, 2^1649906971 is an apocalyptic number.

1649906971 is a deficient number, since it is larger than the sum of its proper divisors (86837229).

1649906971 is an equidigital number, since it uses as much as digits as its factorization.

1649906971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86837228.

The product of its (nonzero) digits is 734832, while the sum is 52.

The square root of 1649906971 is about 40619.0468992073. The cubic root of 1649906971 is about 1181.6435421343.

The spelling of 1649906971 in words is "one billion, six hundred forty-nine million, nine hundred six thousand, nine hundred seventy-one".