121537621 has 2 divisors, whose sum is σ = 121537622. Its totient is φ = 121537620.

The previous prime is 121537583. The next prime is 121537649. The reversal of 121537621 is 126735121.

It is a happy number.

It is an a-pointer prime, because the next prime (121537649) can be obtained adding 121537621 to its sum of digits (28).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 114725521 + 6812100 = 10711^2 + 2610^2 .

It is an emirp because it is prime and its reverse (126735121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 121537621 - 2²¹ = 119440469 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 121537621.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121537021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60768810 + 60768811.

It is an arithmetic number, because the mean of its divisors is an integer number (60768811).

Almost surely, 2^121537621 is an apocalyptic number.

It is an amenable number.

121537621 is a deficient number, since it is larger than the sum of its proper divisors (1).

121537621 is an equidigital number, since it uses as much as digits as its factorization.

121537621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2520, while the sum is 28.

The square root of 121537621 is about 11024.4102336588. The cubic root of 121537621 is about 495.3402021432.

The spelling of 121537621 in words is "one hundred twenty-one million, five hundred thirty-seven thousand, six hundred twenty-one".