4921978 has 4 divisors (see below), whose sum is σ = 7382970. Its totient is φ = 2460988.

The previous prime is 4921949. The next prime is 4922011. The reversal of 4921978 is 8791294.

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., 4915089 + 6889 = 2217^2 + 83^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a d-powerful number, because it can be written as 4⁵ + 9⁴ + 2¹⁷ + 1 + 9⁷ + 7³ + 8 .

It is a self number, because there is not a number n which added to its sum of digits gives 4921978.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1230493 + ... + 1230496.

Almost surely, 2^4921978 is an apocalyptic number.

4921978 is a deficient number, since it is larger than the sum of its proper divisors (2460992).

4921978 is a wasteful number, since it uses less digits than its factorization.

4921978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2460991.

The product of its digits is 36288, while the sum is 40.

The square root of 4921978 is about 2218.5531321111. The cubic root of 4921978 is about 170.1034894666.

The spelling of 4921978 in words is "four million, nine hundred twenty-one thousand, nine hundred seventy-eight".