1621281 has 8 divisors (see below), whose sum is σ = 2170624. Its totient is φ = 1076400.

The previous prime is 1621259. The next prime is 1621283. The reversal of 1621281 is 1821261.

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

It is not a de Polignac number, because 1621281 - 2⁷ = 1621153 is a prime.

It is a super-2 number, since 2×1621281² = 5257104161922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1621283) 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, 145 + ... + 1806.

It is an arithmetic number, because the mean of its divisors is an integer number (271328).

2^1621281 is an apocalyptic number.

It is an amenable number.

1621281 is a deficient number, since it is larger than the sum of its proper divisors (549343).

1621281 is a wasteful number, since it uses less digits than its factorization.

1621281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2231.

The product of its digits is 192, while the sum is 21.

The square root of 1621281 is about 1273.2953310210. The cubic root of 1621281 is about 117.4769775325.

The spelling of 1621281 in words is "one million, six hundred twenty-one thousand, two hundred eighty-one".