2921978 has 4 divisors (see below), whose sum is σ = 4382970. Its totient is φ = 1460988.

The previous prime is 2921957. The next prime is 2921981. The reversal of 2921978 is 8791292.

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., 2455489 + 466489 = 1567^2 + 683^2 .

It is a d-powerful number, because it can be written as 2⁵ + 9 + 2²¹ + 1 + 9³ + 7⁷ + 8³ .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 730493 + ... + 730496.

2^2921978 is an apocalyptic number.

2921978 is a deficient number, since it is larger than the sum of its proper divisors (1460992).

2921978 is a wasteful number, since it uses less digits than its factorization.

2921978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1460991.

The product of its digits is 18144, while the sum is 38.

The square root of 2921978 is about 1709.3794195555. The cubic root of 2921978 is about 142.9636564690.

The spelling of 2921978 in words is "two million, nine hundred twenty-one thousand, nine hundred seventy-eight".