1921140431 has 4 divisors (see below), whose sum is σ = 2195589072. Its totient is φ = 1646691792.

The previous prime is 1921140413. The next prime is 1921140439. The reversal of 1921140431 is 1340411291.

It is a happy number.

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 1921140431 - 2⁶ = 1921140367 is a prime.

It is a super-4 number, since 4×1921140431⁴ (a number of 38 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

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 1921140431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1921140439) 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, 137224310 + ... + 137224323.

It is an arithmetic number, because the mean of its divisors is an integer number (548897268).

Almost surely, 2^1921140431 is an apocalyptic number.

1921140431 is a deficient number, since it is larger than the sum of its proper divisors (274448641).

1921140431 is an equidigital number, since it uses as much as digits as its factorization.

1921140431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 274448640.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 1921140431 is about 43830.8159974235. The cubic root of 1921140431 is about 1243.1390359167.

The spelling of 1921140431 in words is "one billion, nine hundred twenty-one million, one hundred forty thousand, four hundred thirty-one".