189497778731 has 4 divisors (see below), whose sum is σ = 191373994464. Its totient is φ = 187621563000.

The previous prime is 189497778689. The next prime is 189497778739. The reversal of 189497778731 is 137877794981.

189497778731 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 189497778731 - 2⁶ = 189497778667 is a prime.

It is a super-2 number, since 2×189497778731² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (189497778739) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 938107715 + ... + 938107916.

It is an arithmetic number, because the mean of its divisors is an integer number (47843498616).

Almost surely, 2^189497778731 is an apocalyptic number.

189497778731 is a deficient number, since it is larger than the sum of its proper divisors (1876215733).

189497778731 is a wasteful number, since it uses less digits than its factorization.

189497778731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1876215732.

The product of its digits is 149361408, while the sum is 71.

The spelling of 189497778731 in words is "one hundred eighty-nine billion, four hundred ninety-seven million, seven hundred seventy-eight thousand, seven hundred thirty-one".