1540006621 has 2 divisors, whose sum is σ = 1540006622. Its totient is φ = 1540006620.

The previous prime is 1540006619. The next prime is 1540006679. The reversal of 1540006621 is 1266000451.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1528028100 + 11978521 = 39090^2 + 3461^2 .

It is a cyclic number.

It is not a de Polignac number, because 1540006621 - 2¹ = 1540006619 is a prime.

It is a super-3 number, since 3×1540006621³ (a number of 29 digits) contains 333 as substring.

Together with 1540006619, 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 (1540006121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 770003310 + 770003311.

It is an arithmetic number, because the mean of its divisors is an integer number (770003311).

Almost surely, 2^1540006621 is an apocalyptic number.

It is an amenable number.

1540006621 is a deficient number, since it is larger than the sum of its proper divisors (1).

1540006621 is an equidigital number, since it uses as much as digits as its factorization.

1540006621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 1540006621 is about 39242.9180999579. The cubic root of 1540006621 is about 1154.8020052531.

The spelling of 1540006621 in words is "one billion, five hundred forty million, six thousand, six hundred twenty-one".