1021649 has 8 divisors (see below), whose sum is σ = 1139040. Its totient is φ = 910656.

The previous prime is 1021627. The next prime is 1021651. The reversal of 1021649 is 9461201.

It is a happy number.

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

It is not a de Polignac number, because 1021649 - 2¹² = 1017553 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1021849) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1259 + ... + 1904.

It is an arithmetic number, because the mean of its divisors is an integer number (142380).

2^1021649 is an apocalyptic number.

1021649 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

1021649 is a deficient number, since it is larger than the sum of its proper divisors (117391).

1021649 is a wasteful number, since it uses less digits than its factorization.

1021649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3199.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 1021649 is about 1010.7665407996. The cubic root of 1021649 is about 100.7164875291.

The spelling of 1021649 in words is "one million, twenty-one thousand, six hundred forty-nine".