1240740421 has 2 divisors, whose sum is σ = 1240740422. Its totient is φ = 1240740420.

The previous prime is 1240740419. The next prime is 1240740443. The reversal of 1240740421 is 1240470421.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1203396100 + 37344321 = 34690^2 + 6111^2 .

It is a cyclic number.

It is not a de Polignac number, because 1240740421 - 2¹ = 1240740419 is a prime.

Together with 1240740419, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1240740491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 620370210 + 620370211.

It is an arithmetic number, because the mean of its divisors is an integer number (620370211).

Almost surely, 2^1240740421 is an apocalyptic number.

It is an amenable number.

1240740421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1240740421 is an equidigital number, since it uses as much as digits as its factorization.

1240740421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1792, while the sum is 25.

The square root of 1240740421 is about 35224.1454261136. The cubic root of 1240740421 is about 1074.5508622400.

The spelling of 1240740421 in words is "one billion, two hundred forty million, seven hundred forty thousand, four hundred twenty-one".