1981377 has 12 divisors (see below), whose sum is σ = 3012880. Its totient is φ = 1251288.

The previous prime is 1981361. The next prime is 1981393. The reversal of 1981377 is 7731891.

It is an interprime number because it is at equal distance from previous prime (1981361) and next prime (1981393).

It is not a de Polignac number, because 1981377 - 2⁴ = 1981361 is a prime.

It is a super-3 number, since 3×1981377³ = 23335795314051688899, which contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1981337) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5623 + ... + 5964.

2^1981377 is an apocalyptic number.

It is an amenable number.

1981377 is a deficient number, since it is larger than the sum of its proper divisors (1031503).

1981377 is a wasteful number, since it uses less digits than its factorization.

1981377 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11612 (or 11609 counting only the distinct ones).

The product of its digits is 10584, while the sum is 36.

The square root of 1981377 is about 1407.6139385499. The cubic root of 1981377 is about 125.5998263957.

The spelling of 1981377 in words is "one million, nine hundred eighty-one thousand, three hundred seventy-seven".