61511969 has 2 divisors, whose sum is σ = 61511970. Its totient is φ = 61511968.

The previous prime is 61511953. The next prime is 61511971. The reversal of 61511969 is 96911516.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 57760000 + 3751969 = 7600^2 + 1937^2 .

It is a cyclic number.

It is not a de Polignac number, because 61511969 - 2⁴ = 61511953 is a prime.

It is a super-2 number, since 2×61511969² = 7567444660513922, which contains 22 as substring.

Together with 61511971, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (61511939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30755984 + 30755985.

It is an arithmetic number, because the mean of its divisors is an integer number (30755985).

Almost surely, 2^61511969 is an apocalyptic number.

It is an amenable number.

61511969 is a deficient number, since it is larger than the sum of its proper divisors (1).

61511969 is an equidigital number, since it uses as much as digits as its factorization.

61511969 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14580, while the sum is 38.

The square root of 61511969 is about 7842.9566491216. The cubic root of 61511969 is about 394.7479436631.

The spelling of 61511969 in words is "sixty-one million, five hundred eleven thousand, nine hundred sixty-nine".