390969421 has 4 divisors (see below), whose sum is σ = 391012000. Its totient is φ = 390926844.

The previous prime is 390969419. The next prime is 390969457. The reversal of 390969421 is 124969093.

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 a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 390969421 - 2¹ = 390969419 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 (390969221) 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, 1191 + ... + 27988.

It is an arithmetic number, because the mean of its divisors is an integer number (97753000).

Almost surely, 2^390969421 is an apocalyptic number.

It is an amenable number.

390969421 is a deficient number, since it is larger than the sum of its proper divisors (42579).

390969421 is a wasteful number, since it uses less digits than its factorization.

390969421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42578.

The product of its (nonzero) digits is 104976, while the sum is 43.

The square root of 390969421 is about 19772.9466949163. The cubic root of 390969421 is about 731.2192179703.

The spelling of 390969421 in words is "three hundred ninety million, nine hundred sixty-nine thousand, four hundred twenty-one".