1293990161781 has 4 divisors (see below), whose sum is σ = 1725320215712. Its totient is φ = 862660107852.

The previous prime is 1293990161777. The next prime is 1293990161851. The reversal of 1293990161781 is 1871610993921.

It is a happy number.

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 not a de Polignac number, because 1293990161781 - 2² = 1293990161777 is a prime.

It is a super-2 number, since 2×1293990161781² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1293990161081) 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, 215665026961 + ... + 215665026966.

It is an arithmetic number, because the mean of its divisors is an integer number (431330053928).

Almost surely, 2^{1293990161781} is an apocalyptic number.

It is an amenable number.

1293990161781 is a deficient number, since it is larger than the sum of its proper divisors (431330053931).

1293990161781 is an equidigital number, since it uses as much as digits as its factorization.

1293990161781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 431330053930.

The product of its (nonzero) digits is 1469664, while the sum is 57.

The spelling of 1293990161781 in words is "one trillion, two hundred ninety-three billion, nine hundred ninety million, one hundred sixty-one thousand, seven hundred eighty-one".