1390936421 has 4 divisors (see below), whose sum is σ = 1589641632. Its totient is φ = 1192231212.

The previous prime is 1390936403. The next prime is 1390936429. The reversal of 1390936421 is 1246390931.

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: 1246390931 = 223 ⋅5589197.

It is a cyclic number.

It is not a de Polignac number, because 1390936421 - 2²² = 1386742117 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 (1390936429) 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, 99352595 + ... + 99352608.

It is an arithmetic number, because the mean of its divisors is an integer number (397410408).

Almost surely, 2^1390936421 is an apocalyptic number.

It is an amenable number.

1390936421 is a deficient number, since it is larger than the sum of its proper divisors (198705211).

1390936421 is an equidigital number, since it uses as much as digits as its factorization.

1390936421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198705210.

The product of its (nonzero) digits is 34992, while the sum is 38.

The square root of 1390936421 is about 37295.2600339507. The cubic root of 1390936421 is about 1116.2695884492.

The spelling of 1390936421 in words is "one billion, three hundred ninety million, nine hundred thirty-six thousand, four hundred twenty-one".