1621287 has 12 divisors (see below), whose sum is σ = 2359344. Its totient is φ = 1072800.

The previous prime is 1621283. The next prime is 1621309. The reversal of 1621287 is 7821261.

It is not a de Polignac number, because 1621287 - 2² = 1621283 is a prime.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 1621287.

It is a congruent 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 11 ways as a sum of consecutive naturals, for example, 763 + ... + 1955.

It is an arithmetic number, because the mean of its divisors is an integer number (196612).

2^1621287 is an apocalyptic number.

1621287 is a deficient number, since it is larger than the sum of its proper divisors (738057).

1621287 is a wasteful number, since it uses less digits than its factorization.

1621287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1350 (or 1347 counting only the distinct ones).

The product of its digits is 1344, while the sum is 27.

The square root of 1621287 is about 1273.2976871101. The cubic root of 1621287 is about 117.4771224511.

The spelling of 1621287 in words is "one million, six hundred twenty-one thousand, two hundred eighty-seven".