25661511601982 has 4 divisors (see below), whose sum is σ = 38492267402976. Its totient is φ = 12830755800990.

The previous prime is 25661511601981. The next prime is 25661511602011. The reversal of 25661511601982 is 28910611516652.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25661511601981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6415377900494 + ... + 6415377900497.

It is an arithmetic number, because the mean of its divisors is an integer number (9623066850744).

Almost surely, 2^{25661511601982} is an apocalyptic number.

25661511601982 is a deficient number, since it is larger than the sum of its proper divisors (12830755800994).

25661511601982 is a wasteful number, since it uses less digits than its factorization.

25661511601982 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12830755800993.

The product of its (nonzero) digits is 1555200, while the sum is 53.

The spelling of 25661511601982 in words is "twenty-five trillion, six hundred sixty-one billion, five hundred eleven million, six hundred one thousand, nine hundred eighty-two".