25140781 has 4 divisors (see below), whose sum is σ = 26464000. Its totient is φ = 23817564.

The previous prime is 25140779. The next prime is 25140799. The reversal of 25140781 is 18704152.

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 not a de Polignac number, because 25140781 - 2¹ = 25140779 is a prime.

It is a super-2 number, since 2×25140781² = 1264117738579922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25140761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 661581 + ... + 661618.

It is an arithmetic number, because the mean of its divisors is an integer number (6616000).

Almost surely, 2^25140781 is an apocalyptic number.

It is an amenable number.

25140781 is a deficient number, since it is larger than the sum of its proper divisors (1323219).

25140781 is a wasteful number, since it uses less digits than its factorization.

25140781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1323218.

The product of its (nonzero) digits is 2240, while the sum is 28.

The square root of 25140781 is about 5014.0583363180. The cubic root of 25140781 is about 292.9496082970.

It can be divided in two parts, 25140 and 781, that added together give a square (25921 = 161²).

The spelling of 25140781 in words is "twenty-five million, one hundred forty thousand, seven hundred eighty-one".