61919621 has 2 divisors, whose sum is σ = 61919622. Its totient is φ = 61919620.

The previous prime is 61919609. The next prime is 61919623. The reversal of 61919621 is 12691916.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60996100 + 923521 = 7810^2 + 961^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61919621 is a prime.

Together with 61919623, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61919623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30959810 + 30959811.

It is an arithmetic number, because the mean of its divisors is an integer number (30959811).

Almost surely, 2^61919621 is an apocalyptic number.

It is an amenable number.

61919621 is a deficient number, since it is larger than the sum of its proper divisors (1).

61919621 is an equidigital number, since it uses as much as digits as its factorization.

61919621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5832, while the sum is 35.

The square root of 61919621 is about 7868.9021470597. The cubic root of 61919621 is about 395.6180486306.

The spelling of 61919621 in words is "sixty-one million, nine hundred nineteen thousand, six hundred twenty-one".