1231720157358 has 12 divisors (see below), whose sum is σ = 2668727007648. Its totient is φ = 410573385780.

The previous prime is 1231720157321. The next prime is 1231720157387. The reversal of 1231720157358 is 8537510271321.

1231720157358 is a `hidden beast` number, since 1 + 2 + 3 + 1 + 7 + 20 + 1 + 573 + 58 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 34214448798 + ... + 34214448833.

It is an arithmetic number, because the mean of its divisors is an integer number (222393917304).

Almost surely, 2^{1231720157358} is an apocalyptic number.

1231720157358 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1231720157358 is an abundant number, since it is smaller than the sum of its proper divisors (1437006850290).

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

1231720157358 is a wasteful number, since it uses less digits than its factorization.

1231720157358 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68428897639 (or 68428897636 counting only the distinct ones).

The product of its (nonzero) digits is 352800, while the sum is 45.

The spelling of 1231720157358 in words is "one trillion, two hundred thirty-one billion, seven hundred twenty million, one hundred fifty-seven thousand, three hundred fifty-eight".