211220321245 has 16 divisors (see below), whose sum is σ = 256118934960. Its totient is φ = 167207122944.

The previous prime is 211220321233. The next prime is 211220321251. The reversal of 211220321245 is 542123022112.

It can be written as a sum of positive squares in 8 ways, for example, as 26013173796 + 185207147449 = 161286^2 + 430357^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211220321245 is a prime.

It is a super-2 number, since 2×211220321245² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3280179 + ... + 3343951.

It is an arithmetic number, because the mean of its divisors is an integer number (16007433435).

Almost surely, 2^211220321245 is an apocalyptic number.

It is an amenable number.

211220321245 is a deficient number, since it is larger than the sum of its proper divisors (44898613715).

211220321245 is an equidigital number, since it uses as much as digits as its factorization.

211220321245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70704.

The product of its (nonzero) digits is 1920, while the sum is 25.

Adding to 211220321245 its reverse (542123022112), we get a palindrome (753343343357).

The spelling of 211220321245 in words is "two hundred eleven billion, two hundred twenty million, three hundred twenty-one thousand, two hundred forty-five".