21394001383225 has 9 divisors (see below), whose sum is σ = 26528590392493. Its totient is φ = 17115182605120.

The previous prime is 21394001383151. The next prime is 21394001383231. The reversal of 21394001383225 is 52238310049312.

The square root of 21394001383225 is 4625365.

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

It can be written as a sum of positive squares in 4 ways, for example, as 2621850739369 + 18772150643856 = 1619213^2 + 4332684^2 .

It is not a de Polignac number, because 21394001383225 - 2²⁹ = 21393464512313 is a prime.

It is a super-2 number, since 2×21394001383225² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 22664289 + ... + 23589361.

Almost surely, 2^{21394001383225} is an apocalyptic number.

21394001383225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21394001383225 is the 4625365-th square number.

21394001383225 is the 2312683-rd centered octagonal number.

It is an amenable number.

21394001383225 is a deficient number, since it is larger than the sum of its proper divisors (5134589009268).

21394001383225 is an frugal number, since it uses more digits than its factorization.

21394001383225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1850156 (or 925078 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 43.

The spelling of 21394001383225 in words is "twenty-one trillion, three hundred ninety-four billion, one million, three hundred eighty-three thousand, two hundred twenty-five".