211520661701 has 4 divisors (see below), whose sum is σ = 212523129504. Its totient is φ = 210518193900.

The previous prime is 211520661697. The next prime is 211520661721. The reversal of 211520661701 is 107166025112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 211520661701 - 2² = 211520661697 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211520661721) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 501233585 + ... + 501234006.

It is an arithmetic number, because the mean of its divisors is an integer number (53130782376).

Almost surely, 2^211520661701 is an apocalyptic number.

It is an amenable number.

211520661701 is a deficient number, since it is larger than the sum of its proper divisors (1002467803).

211520661701 is a wasteful number, since it uses less digits than its factorization.

211520661701 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1002467802.

The product of its (nonzero) digits is 5040, while the sum is 32.

Adding to 211520661701 its reverse (107166025112), we get a palindrome (318686686813).

The spelling of 211520661701 in words is "two hundred eleven billion, five hundred twenty million, six hundred sixty-one thousand, seven hundred one".