691220110102001 has 4 divisors (see below), whose sum is σ = 691223362181604. Its totient is φ = 691216858022400.

The previous prime is 691220110101967. The next prime is 691220110102069. The reversal of 691220110102001 is 100201011022196.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 677970153379600 + 13249956722401 = 26037860^2 + 3640049^2 .

It is a cyclic number.

It is not a de Polignac number, because 691220110102001 - 2²² = 691220105907697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (691220110102091) 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, 1625720960 + ... + 1626146081.

It is an arithmetic number, because the mean of its divisors is an integer number (172805840545401).

Almost surely, 2^{691220110102001} is an apocalyptic number.

It is an amenable number.

691220110102001 is a deficient number, since it is larger than the sum of its proper divisors (3252079603).

691220110102001 is a wasteful number, since it uses less digits than its factorization.

691220110102001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3252079602.

The product of its (nonzero) digits is 432, while the sum is 26.

Adding to 691220110102001 its reverse (100201011022196), we get a palindrome (791421121124197).

The spelling of 691220110102001 in words is "six hundred ninety-one trillion, two hundred twenty billion, one hundred ten million, one hundred two thousand, one".