1406657421 has 40 divisors (see below), whose sum is σ = 2274764184. Its totient is φ = 861114240.

The previous prime is 1406657411. The next prime is 1406657449. The reversal of 1406657421 is 1247566041.

1406657421 is a `hidden beast` number, since 1 + 4 + 0 + 66 + 574 + 21 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 306740196 + 1099917225 = 17514^2 + 33165^2 .

It is not a de Polignac number, because 1406657421 - 2²⁹ = 869786509 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1406657411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 204051 + ... + 210831.

Almost surely, 2^1406657421 is an apocalyptic number.

It is an amenable number.

1406657421 is a deficient number, since it is larger than the sum of its proper divisors (868106763).

1406657421 is a wasteful number, since it uses less digits than its factorization.

1406657421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7003 (or 6994 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

The square root of 1406657421 is about 37505.4318865948. The cubic root of 1406657421 is about 1120.4593728381.

The spelling of 1406657421 in words is "one billion, four hundred six million, six hundred fifty-seven thousand, four hundred twenty-one".