1431891661 has 8 divisors (see below), whose sum is σ = 1507705920. Its totient is φ = 1356122592.

The previous prime is 1431891649. The next prime is 1431891673. The reversal of 1431891661 is 1661981341.

It is an interprime number because it is at equal distance from previous prime (1431891649) and next prime (1431891673).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1431891661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1431891641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68136 + ... + 86638.

It is an arithmetic number, because the mean of its divisors is an integer number (188463240).

Almost surely, 2^1431891661 is an apocalyptic number.

It is an amenable number.

1431891661 is a deficient number, since it is larger than the sum of its proper divisors (75814259).

1431891661 is a wasteful number, since it uses less digits than its factorization.

1431891661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22595.

The product of its digits is 31104, while the sum is 40.

The square root of 1431891661 is about 37840.3443562555. The cubic root of 1431891661 is about 1127.1197331211.

The spelling of 1431891661 in words is "one billion, four hundred thirty-one million, eight hundred ninety-one thousand, six hundred sixty-one".