21771136062025 has 81 divisors (see below), whose sum is σ = 32531058582399. Its totient is φ = 14410858008960.

The previous prime is 21771136062023. The next prime is 21771136062029. The reversal of 21771136062025 is 52026063117712.

It is a happy number.

The square root of 21771136062025 is 4665955.

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

It can be written as a sum of positive squares in 13 ways, for example, as 21255686731321 + 515449330704 = 4610389^2 + 717948^2 .

It is not a de Polignac number, because 21771136062025 - 2¹ = 21771136062023 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21771136062023) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 4735942027 + ... + 4735946623.

Almost surely, 2^{21771136062025} is an apocalyptic number.

21771136062025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21771136062025 is the 4665955-th square number.

21771136062025 is the 2332978-th centered octagonal number.

It is an amenable number.

21771136062025 is a deficient number, since it is larger than the sum of its proper divisors (10759922520374).

21771136062025 is an frugal number, since it uses more digits than its factorization.

21771136062025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9276 (or 4638 counting only the distinct ones).

The product of its (nonzero) digits is 211680, while the sum is 43.

Adding to 21771136062025 its reverse (52026063117712), we get a palindrome (73797199179737).

The spelling of 21771136062025 in words is "twenty-one trillion, seven hundred seventy-one billion, one hundred thirty-six million, sixty-two thousand, twenty-five".