25643402 has 4 divisors (see below), whose sum is σ = 38465106. Its totient is φ = 12821700.

The previous prime is 25643389. The next prime is 25643419. The reversal of 25643402 is 20434652.

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., 18412681 + 7230721 = 4291^2 + 2689^2 .

It is a super-2 number, since 2×25643402² = 1315168132267208, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6410849 + ... + 6410852.

Almost surely, 2^25643402 is an apocalyptic number.

25643402 is a deficient number, since it is larger than the sum of its proper divisors (12821704).

25643402 is a wasteful number, since it uses less digits than its factorization.

25643402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12821703.

The product of its (nonzero) digits is 5760, while the sum is 26.

The square root of 25643402 is about 5063.9314766296. The cubic root of 25643402 is about 294.8889824527. Note that the first 3 decimals are identical.

The spelling of 25643402 in words is "twenty-five million, six hundred forty-three thousand, four hundred two".