1238697992561 has 4 divisors (see below), whose sum is σ = 1262069652852. Its totient is φ = 1215326332272.

The previous prime is 1238697992531. The next prime is 1238697992573. The reversal of 1238697992561 is 1652997968321.

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 1083745542961 + 154952449600 = 1041031^2 + 393640^2 .

It is a cyclic number.

It is not a de Polignac number, because 1238697992561 - 2¹⁴ = 1238697976177 is a prime.

It is a super-2 number, since 2×1238697992561² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1238697992491 and 1238697992500.

It is not an unprimeable number, because it can be changed into a prime (1238697992531) 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, 11685830066 + ... + 11685830171.

It is an arithmetic number, because the mean of its divisors is an integer number (315517413213).

Almost surely, 2^{1238697992561} is an apocalyptic number.

It is an amenable number.

1238697992561 is a deficient number, since it is larger than the sum of its proper divisors (23371660291).

1238697992561 is an equidigital number, since it uses as much as digits as its factorization.

1238697992561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23371660290.

The product of its digits is 88179840, while the sum is 68.

The spelling of 1238697992561 in words is "one trillion, two hundred thirty-eight billion, six hundred ninety-seven million, nine hundred ninety-two thousand, five hundred sixty-one".