1242992021 has 2 divisors, whose sum is σ = 1242992022. Its totient is φ = 1242992020.

The previous prime is 1242992017. The next prime is 1242992029. The reversal of 1242992021 is 1202992421.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1217032996 + 25959025 = 34886^2 + 5095^2 .

It is a cyclic number.

It is not a de Polignac number, because 1242992021 - 2² = 1242992017 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1242992029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621496010 + 621496011.

It is an arithmetic number, because the mean of its divisors is an integer number (621496011).

Almost surely, 2^1242992021 is an apocalyptic number.

It is an amenable number.

1242992021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1242992021 is an equidigital number, since it uses as much as digits as its factorization.

1242992021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 1242992021 is about 35256.0919700411. The cubic root of 1242992021 is about 1075.2004734467.

The spelling of 1242992021 in words is "one billion, two hundred forty-two million, nine hundred ninety-two thousand, twenty-one".