1981508 has 6 divisors (see below), whose sum is σ = 3467646. Its totient is φ = 990752.

The previous prime is 1981493. The next prime is 1981513. The reversal of 1981508 is 8051891.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 1044484 + 937024 = 1022^2 + 968^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 247685 + ... + 247692.

It is an arithmetic number, because the mean of its divisors is an integer number (577941).

2^1981508 is an apocalyptic number.

It is an amenable number.

1981508 is a deficient number, since it is larger than the sum of its proper divisors (1486138).

1981508 is a wasteful number, since it uses less digits than its factorization.

1981508 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 495381 (or 495379 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 32.

The square root of 1981508 is about 1407.6604704260. The cubic root of 1981508 is about 125.6025943721.

The spelling of 1981508 in words is "one million, nine hundred eighty-one thousand, five hundred eight".