1977021 has 16 divisors (see below), whose sum is σ = 3009600. Its totient is φ = 1281744.

The previous prime is 1976993. The next prime is 1977023. The reversal of 1977021 is 1207791.

It is not a de Polignac number, because 1977021 - 2¹⁰ = 1975997 is a prime.

It is a super-2 number, since 2×1977021² = 7817224068882, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1977023) 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 15 ways as a sum of consecutive naturals, for example, 10 + ... + 1988.

It is an arithmetic number, because the mean of its divisors is an integer number (188100).

2^1977021 is an apocalyptic number.

It is an amenable number.

1977021 is a deficient number, since it is larger than the sum of its proper divisors (1032579).

1977021 is a wasteful number, since it uses less digits than its factorization.

1977021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2025 (or 2019 counting only the distinct ones).

The product of its (nonzero) digits is 882, while the sum is 27.

The square root of 1977021 is about 1406.0657879345. The cubic root of 1977021 is about 125.5077163343.

It can be divided in two parts, 19770 and 21, that added together give a palindrome (19791).

The spelling of 1977021 in words is "one million, nine hundred seventy-seven thousand, twenty-one".