101780431 has 4 divisors (see below), whose sum is σ = 102428872. Its totient is φ = 101131992.

The previous prime is 101780429. The next prime is 101780443. The reversal of 101780431 is 134087101.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 134087101 = 1579 ⋅84919.

It is a cyclic number.

It is not a de Polignac number, because 101780431 - 2¹ = 101780429 is a prime.

It is a super-2 number, since 2×101780431² = 20718512269091522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 101780396 and 101780405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (101780461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 323985 + ... + 324298.

It is an arithmetic number, because the mean of its divisors is an integer number (25607218).

Almost surely, 2^101780431 is an apocalyptic number.

101780431 is a deficient number, since it is larger than the sum of its proper divisors (648441).

101780431 is an equidigital number, since it uses as much as digits as its factorization.

101780431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 648440.

The product of its (nonzero) digits is 672, while the sum is 25.

The square root of 101780431 is about 10088.6287968187. The cubic root of 101780431 is about 466.8973710194.

The spelling of 101780431 in words is "one hundred one million, seven hundred eighty thousand, four hundred thirty-one".