2515978 has 4 divisors (see below), whose sum is σ = 3773970. Its totient is φ = 1257988.

The previous prime is 2515967. The next prime is 2516021. The reversal of 2515978 is 8795152.

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., 2122849 + 393129 = 1457^2 + 627^2 .

It is an Ulam number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 628993 + ... + 628996.

2^2515978 is an apocalyptic number.

2515978 is a deficient number, since it is larger than the sum of its proper divisors (1257992).

2515978 is a wasteful number, since it uses less digits than its factorization.

2515978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1257991.

The product of its digits is 25200, while the sum is 37.

The square root of 2515978 is about 1586.1834698420. The cubic root of 2515978 is about 136.0094067888.

The spelling of 2515978 in words is "two million, five hundred fifteen thousand, nine hundred seventy-eight".