20429657 has 2 divisors, whose sum is σ = 20429658. Its totient is φ = 20429656.

The previous prime is 20429627. The next prime is 20429663. The reversal of 20429657 is 75692402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20286016 + 143641 = 4504^2 + 379^2 .

It is a cyclic number.

It is not a de Polignac number, because 20429657 - 2⁶ = 20429593 is a prime.

It is not a weakly prime, because it can be changed into another prime (20429627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10214828 + 10214829.

It is an arithmetic number, because the mean of its divisors is an integer number (10214829).

Almost surely, 2^20429657 is an apocalyptic number.

It is an amenable number.

20429657 is a deficient number, since it is larger than the sum of its proper divisors (1).

20429657 is an equidigital number, since it uses as much as digits as its factorization.

20429657 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30240, while the sum is 35.

The square root of 20429657 is about 4519.9178089872. The cubic root of 20429657 is about 273.3717870085.

The spelling of 20429657 in words is "twenty million, four hundred twenty-nine thousand, six hundred fifty-seven".