1989157481 has 8 divisors (see below), whose sum is σ = 2150441280. Its totient is φ = 1833532848.

The previous prime is 1989157477. The next prime is 1989157483. The reversal of 1989157481 is 1847519891.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 1989157481 - 2² = 1989157477 is a prime.

It is a super-2 number, since 2×1989157481² = 7913494968436530722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1989157483) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1414061 + ... + 1415466.

It is an arithmetic number, because the mean of its divisors is an integer number (268805160).

Almost surely, 2^1989157481 is an apocalyptic number.

It is an amenable number.

1989157481 is a deficient number, since it is larger than the sum of its proper divisors (161283799).

1989157481 is a wasteful number, since it uses less digits than its factorization.

1989157481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2829583.

The product of its digits is 725760, while the sum is 53.

The square root of 1989157481 is about 44599.9717600807. The cubic root of 1989157481 is about 1257.6401367881.

The spelling of 1989157481 in words is "one billion, nine hundred eighty-nine million, one hundred fifty-seven thousand, four hundred eighty-one".