2721978 has 64 divisors (see below), whose sum is σ = 7296000. Its totient is φ = 734832.

The previous prime is 2721947. The next prime is 2722001. The reversal of 2721978 is 8791272.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6993 + ... + 7371.

It is an arithmetic number, because the mean of its divisors is an integer number (114000).

2^2721978 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2721978, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3648000).

2721978 is an abundant number, since it is smaller than the sum of its proper divisors (4574022).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2721978 is a wasteful number, since it uses less digits than its factorization.

2721978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 416 (or 410 counting only the distinct ones).

The product of its digits is 14112, while the sum is 36.

The square root of 2721978 is about 1649.8418105988. The cubic root of 2721978 is about 139.6244697844.

The spelling of 2721978 in words is "two million, seven hundred twenty-one thousand, nine hundred seventy-eight".