4975661821 has 8 divisors (see below), whose sum is σ = 5359342464. Its totient is φ = 4592115120.

The previous prime is 4975661797. The next prime is 4975661827. The reversal of 4975661821 is 1281665794.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 4975661821 - 2⁷ = 4975661693 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4975661827) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 51720 + ... + 112366.

It is an arithmetic number, because the mean of its divisors is an integer number (669917808).

Almost surely, 2^4975661821 is an apocalyptic number.

It is an amenable number.

4975661821 is a deficient number, since it is larger than the sum of its proper divisors (383680643).

4975661821 is a wasteful number, since it uses less digits than its factorization.

4975661821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66971.

The product of its digits is 725760, while the sum is 49.

The square root of 4975661821 is about 70538.3712669920. The cubic root of 4975661821 is about 1707.1969193112.

The spelling of 4975661821 in words is "four billion, nine hundred seventy-five million, six hundred sixty-one thousand, eight hundred twenty-one".