1651642 has 4 divisors (see below), whose sum is σ = 2477466. Its totient is φ = 825820.

The previous prime is 1651621. The next prime is 1651667. The reversal of 1651642 is 2461561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 2461561 = 79 ⋅31159.

It can be written as a sum of positive squares in only one way, i.e., 1490841 + 160801 = 1221^2 + 401^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 412909 + ... + 412912.

2^1651642 is an apocalyptic number.

1651642 is a deficient number, since it is larger than the sum of its proper divisors (825824).

1651642 is an equidigital number, since it uses as much as digits as its factorization.

1651642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 825823.

The product of its digits is 1440, while the sum is 25.

The square root of 1651642 is about 1285.1622465666. The cubic root of 1651642 is about 118.2057599334.

The spelling of 1651642 in words is "one million, six hundred fifty-one thousand, six hundred forty-two".