4991971 has 4 divisors (see below), whose sum is σ = 5014000. Its totient is φ = 4969944.

The previous prime is 4991963. The next prime is 4991977. The reversal of 4991971 is 1791994.

It is a happy number.

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 4991971 - 2³ = 4991963 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (4991977) 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, 10671 + ... + 11128.

It is an arithmetic number, because the mean of its divisors is an integer number (1253500).

Almost surely, 2^4991971 is an apocalyptic number.

4991971 is a deficient number, since it is larger than the sum of its proper divisors (22029).

4991971 is a wasteful number, since it uses less digits than its factorization.

4991971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22028.

The product of its digits is 20412, while the sum is 40.

The square root of 4991971 is about 2234.2719172026. The cubic root of 4991971 is about 170.9060163188.

The spelling of 4991971 in words is "four million, nine hundred ninety-one thousand, nine hundred seventy-one".