26630649721 has 9 divisors (see below), whose sum is σ = 28839036429. Its totient is φ = 24580179936.

The previous prime is 26630649701. The next prime is 26630649737. The reversal of 26630649721 is 12794603662.

The square root of 26630649721 is 163189.

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 2982361321 + 23648288400 = 54611^2 + 153780^2 .

It is not a de Polignac number, because 26630649721 - 2¹³ = 26630641529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (26630649701) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2115181 + ... + 2127733.

It is an arithmetic number, because the mean of its divisors is an integer number (3204337381).

Almost surely, 2^26630649721 is an apocalyptic number.

26630649721 is the 163189-th square number.

26630649721 is the 81595-th centered octagonal number.

It is an amenable number.

26630649721 is a deficient number, since it is larger than the sum of its proper divisors (2208386708).

26630649721 is an frugal number, since it uses more digits than its factorization.

26630649721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25132 (or 12566 counting only the distinct ones).

The product of its (nonzero) digits is 653184, while the sum is 46.

The spelling of 26630649721 in words is "twenty-six billion, six hundred thirty million, six hundred forty-nine thousand, seven hundred twenty-one".