25869183921 has 189 divisors, whose sum is σ = 48474601371. Its totient is φ = 13757524704.

The previous prime is 25869183887. The next prime is 25869183929. The reversal of 25869183921 is 12938196852.

The square root of 25869183921 is 160839.

It is a perfect power (a square), and thus also a powerful number.

25869183921 is a `hidden beast` number, since 2 + 586 + 9 + 1 + 8 + 39 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 23148101025 + 2721082896 = 152145^2 + 52164^2 .

It is a tau number, because it is divible by the number of its divisors (189).

It is not a de Polignac number, because 25869183921 - 2⁷ = 25869183793 is a prime.

It is not an unprimeable number, because it can be changed into a prime (25869183929) by changing a digit.

It is a polite number, since it can be written in 188 ways as a sum of consecutive naturals, for example, 699167115 + ... + 699167151.

Almost surely, 2^25869183921 is an apocalyptic number.

25869183921 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

25869183921 is the 160839-th square number.

25869183921 is the 80420-th centered octagonal number.

It is an amenable number.

25869183921 is a deficient number, since it is larger than the sum of its proper divisors (22605417450).

25869183921 is an frugal number, since it uses more digits than its factorization.

25869183921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152 (or 70 counting only the distinct ones).

The product of its digits is 1866240, while the sum is 54.

The spelling of 25869183921 in words is "twenty-five billion, eight hundred sixty-nine million, one hundred eighty-three thousand, nine hundred twenty-one".