25777987 has 4 divisors (see below), whose sum is σ = 25942336. Its totient is φ = 25613640.

The previous prime is 25777943. The next prime is 25777993. The reversal of 25777987 is 78977752.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 25777987 - 2¹⁹ = 25253699 is a prime.

It is a super-2 number, since 2×25777987² = 1329009227544338, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25777907) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 81939 + ... + 82252.

It is an arithmetic number, because the mean of its divisors is an integer number (6485584).

Almost surely, 2^25777987 is an apocalyptic number.

25777987 is a deficient number, since it is larger than the sum of its proper divisors (164349).

25777987 is a wasteful number, since it uses less digits than its factorization.

25777987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164348.

The product of its digits is 1728720, while the sum is 52.

The square root of 25777987 is about 5077.2026747019. The cubic root of 25777987 is about 295.4039739788.

The spelling of 25777987 in words is "twenty-five million, seven hundred seventy-seven thousand, nine hundred eighty-seven".