61447909261 has 2 divisors, whose sum is σ = 61447909262. Its totient is φ = 61447909260.

The previous prime is 61447909231. The next prime is 61447909273. The reversal of 61447909261 is 16290974416.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 56145302500 + 5302606761 = 236950^2 + 72819^2 .

It is a cyclic number.

It is not a de Polignac number, because 61447909261 - 2³³ = 52857974669 is a prime.

It is a super-2 number, since 2×61447909261² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61447909231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30723954630 + 30723954631.

It is an arithmetic number, because the mean of its divisors is an integer number (30723954631).

Almost surely, 2^61447909261 is an apocalyptic number.

It is an amenable number.

61447909261 is a deficient number, since it is larger than the sum of its proper divisors (1).

61447909261 is an equidigital number, since it uses as much as digits as its factorization.

61447909261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 653184, while the sum is 49.

The spelling of 61447909261 in words is "sixty-one billion, four hundred forty-seven million, nine hundred nine thousand, two hundred sixty-one".