1931400385 has 4 divisors (see below), whose sum is σ = 2317680468. Its totient is φ = 1545120304.

The previous prime is 1931400353. The next prime is 1931400389. The reversal of 1931400385 is 5830041391.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1543625521 + 387774864 = 39289^2 + 19692^2 .

It is a cyclic number.

It is not a de Polignac number, because 1931400385 - 2⁵ = 1931400353 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1931400385.

It is not an unprimeable number, because it can be changed into a prime (1931400389) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 193140034 + ... + 193140043.

It is an arithmetic number, because the mean of its divisors is an integer number (579420117).

Almost surely, 2^1931400385 is an apocalyptic number.

It is an amenable number.

1931400385 is a deficient number, since it is larger than the sum of its proper divisors (386280083).

1931400385 is an equidigital number, since it uses as much as digits as its factorization.

1931400385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 386280082.

The product of its (nonzero) digits is 12960, while the sum is 34.

The square root of 1931400385 is about 43947.7005655586. The cubic root of 1931400385 is about 1245.3481249893.

The spelling of 1931400385 in words is "one billion, nine hundred thirty-one million, four hundred thousand, three hundred eighty-five".