991520175419 has 2 divisors, whose sum is σ = 991520175420. Its totient is φ = 991520175418.

The previous prime is 991520175377. The next prime is 991520175473. The reversal of 991520175419 is 914571025199.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 991520175419 - 2¹⁶ = 991520109883 is a prime.

It is a super-2 number, since 2×991520175419² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (991520175319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495760087709 + 495760087710.

It is an arithmetic number, because the mean of its divisors is an integer number (495760087710).

Almost surely, 2^991520175419 is an apocalyptic number.

991520175419 is a deficient number, since it is larger than the sum of its proper divisors (1).

991520175419 is an equidigital number, since it uses as much as digits as its factorization.

991520175419 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1020600, while the sum is 53.

The spelling of 991520175419 in words is "nine hundred ninety-one billion, five hundred twenty million, one hundred seventy-five thousand, four hundred nineteen".