4861991 has 2 divisors, whose sum is σ = 4861992. Its totient is φ = 4861990.

The previous prime is 4861979. The next prime is 4861999. The reversal of 4861991 is 1991684.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 4861991 - 2²² = 667687 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4861999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2430995 + 2430996.

It is an arithmetic number, because the mean of its divisors is an integer number (2430996).

Almost surely, 2^4861991 is an apocalyptic number.

4861991 is a deficient number, since it is larger than the sum of its proper divisors (1).

4861991 is an equidigital number, since it uses as much as digits as its factorization.

4861991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15552, while the sum is 38.

The square root of 4861991 is about 2204.9922902360. The cubic root of 4861991 is about 169.4096129386.

The spelling of 4861991 in words is "four million, eight hundred sixty-one thousand, nine hundred ninety-one".