1290421 has 8 divisors (see below), whose sum is σ = 1427904. Its totient is φ = 1156320.

The previous prime is 1290379. The next prime is 1290427. The reversal of 1290421 is 1240921.

1290421 is a nontrivial binomial coefficient, being equal to C(1607, 2).

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

It is not a de Polignac number, because 1290421 - 2⁷ = 1290293 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1290427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1 + ... + 1606.

It is an arithmetic number, because the mean of its divisors is an integer number (178488).

2^1290421 is an apocalyptic number.

1290421 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1290421 is the 1606-th triangular number.

1290421 is the 536-th centered nonagonal number.

It is an amenable number.

1290421 is a deficient number, since it is larger than the sum of its proper divisors (137483).

1290421 is a wasteful number, since it uses less digits than its factorization.

1290421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1691.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 1290421 is about 1135.9669889570. The cubic root of 1290421 is about 108.8705643111.

It can be divided in two parts, 1290 and 421, that added together give a triangular number (1711 = T₅₈).

The spelling of 1290421 in words is "one million, two hundred ninety thousand, four hundred twenty-one".