1231720157346 has 64 divisors (see below), whose sum is σ = 2980173081600. Its totient is φ = 331882883136.

The previous prime is 1231720157321. The next prime is 1231720157387. The reversal of 1231720157346 is 6437510271321.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 1231720157298 and 1231720157307.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11706516 + ... + 11811263.

It is an arithmetic number, because the mean of its divisors is an integer number (46565204400).

Almost surely, 2^{1231720157346} is an apocalyptic number.

1231720157346 is an abundant number, since it is smaller than the sum of its proper divisors (1748452924254).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1231720157346 is a wasteful number, since it uses less digits than its factorization.

1231720157346 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23517863.

The product of its (nonzero) digits is 211680, while the sum is 42.

The spelling of 1231720157346 in words is "one trillion, two hundred thirty-one billion, seven hundred twenty million, one hundred fifty-seven thousand, three hundred forty-six".