25431423402 has 128 divisors (see below), whose sum is σ = 64538062848. Its totient is φ = 6489100800.

The previous prime is 25431423401. The next prime is 25431423419. The reversal of 25431423402 is 20432413452.

It is a self number, because there is not a number n which added to its sum of digits gives 25431423402.

It is not an unprimeable number, because it can be changed into a prime (25431423401) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 10265788 + ... + 10268264.

It is an arithmetic number, because the mean of its divisors is an integer number (504203616).

Almost surely, 2^25431423402 is an apocalyptic number.

25431423402 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 25431423402, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32269031424).

25431423402 is an abundant number, since it is smaller than the sum of its proper divisors (39106639446).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

25431423402 is a wasteful number, since it uses less digits than its factorization.

25431423402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2884.

The product of its (nonzero) digits is 23040, while the sum is 30.

Adding to 25431423402 its reverse (20432413452), we get a palindrome (45863836854).

The spelling of 25431423402 in words is "twenty-five billion, four hundred thirty-one million, four hundred twenty-three thousand, four hundred two".