61891402501 has 2 divisors, whose sum is σ = 61891402502. Its totient is φ = 61891402500.

The previous prime is 61891402493. The next prime is 61891402619. The reversal of 61891402501 is 10520419816.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 60491894401 + 1399508100 = 245951^2 + 37410^2 .

It is a cyclic number.

It is not a de Polignac number, because 61891402501 - 2³ = 61891402493 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61891402201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30945701250 + 30945701251.

It is an arithmetic number, because the mean of its divisors is an integer number (30945701251).

Almost surely, 2^61891402501 is an apocalyptic number.

It is an amenable number.

61891402501 is a deficient number, since it is larger than the sum of its proper divisors (1).

61891402501 is an equidigital number, since it uses as much as digits as its factorization.

61891402501 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17280, while the sum is 37.

The spelling of 61891402501 in words is "sixty-one billion, eight hundred ninety-one million, four hundred two thousand, five hundred one".