25380721 has 4 divisors (see below), whose sum is σ = 25618032. Its totient is φ = 25143412.

The previous prime is 25380703. The next prime is 25380727. The reversal of 25380721 is 12708352.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 25380721 - 2⁵ = 25380689 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 25380721.

It is not an unprimeable number, because it can be changed into a prime (25380727) 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, 118495 + ... + 118708.

It is an arithmetic number, because the mean of its divisors is an integer number (6404508).

Almost surely, 2^25380721 is an apocalyptic number.

It is an amenable number.

25380721 is a deficient number, since it is larger than the sum of its proper divisors (237311).

25380721 is a wasteful number, since it uses less digits than its factorization.

25380721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 237310.

The product of its (nonzero) digits is 3360, while the sum is 28.

The square root of 25380721 is about 5037.9282448245. The cubic root of 25380721 is about 293.8786154157.

It can be divided in two parts, 253807 and 21, that added together give a triangular number (253828 = T₇₁₂).

The spelling of 25380721 in words is "twenty-five million, three hundred eighty thousand, seven hundred twenty-one".