1989209431 has 16 divisors (see below), whose sum is σ = 2205745920. Its totient is φ = 1778705280.

The previous prime is 1989209377. The next prime is 1989209437. The reversal of 1989209431 is 1349029891.

It is a happy number.

It is not a de Polignac number, because 1989209431 - 2¹³ = 1989201239 is a prime.

It is a super-2 number, since 2×1989209431² = 7913908320758687522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1989209437) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 616735 + ... + 619951.

It is an arithmetic number, because the mean of its divisors is an integer number (137859120).

Almost surely, 2^1989209431 is an apocalyptic number.

1989209431 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1989209431 is a deficient number, since it is larger than the sum of its proper divisors (216536489).

1989209431 is a wasteful number, since it uses less digits than its factorization.

1989209431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4134.

The product of its (nonzero) digits is 139968, while the sum is 46.

The square root of 1989209431 is about 44600.5541557501. The cubic root of 1989209431 is about 1257.6510851146.

The spelling of 1989209431 in words is "one billion, nine hundred eighty-nine million, two hundred nine thousand, four hundred thirty-one".