1400243021 has 4 divisors (see below), whose sum is σ = 1403899392. Its totient is φ = 1396586652.

The previous prime is 1400242997. The next prime is 1400243041. The reversal of 1400243021 is 1203420041.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1203420041 = 193 ⋅6235337.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1400243021 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1400243041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1827611 + ... + 1828376.

It is an arithmetic number, because the mean of its divisors is an integer number (350974848).

Almost surely, 2^1400243021 is an apocalyptic number.

It is an amenable number.

1400243021 is a deficient number, since it is larger than the sum of its proper divisors (3656371).

1400243021 is an equidigital number, since it uses as much as digits as its factorization.

1400243021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3656370.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 1400243021 is about 37419.8212315345. The cubic root of 1400243021 is about 1118.7536680757.

Adding to 1400243021 its reverse (1203420041), we get a palindrome (2603663062).

The spelling of 1400243021 in words is "one billion, four hundred million, two hundred forty-three thousand, twenty-one".