61951029421 has 2 divisors, whose sum is σ = 61951029422. Its totient is φ = 61951029420.

The previous prime is 61951029419. The next prime is 61951029433. The reversal of 61951029421 is 12492015916.

61951029421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 47095076196 + 14855953225 = 217014^2 + 121885^2 .

It is a cyclic number.

It is not a de Polignac number, because 61951029421 - 2¹ = 61951029419 is a prime.

Together with 61951029419, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61951029121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30975514710 + 30975514711.

It is an arithmetic number, because the mean of its divisors is an integer number (30975514711).

Almost surely, 2^61951029421 is an apocalyptic number.

It is an amenable number.

61951029421 is a deficient number, since it is larger than the sum of its proper divisors (1).

61951029421 is an equidigital number, since it uses as much as digits as its factorization.

61951029421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 38880, while the sum is 40.

The spelling of 61951029421 in words is "sixty-one billion, nine hundred fifty-one million, twenty-nine thousand, four hundred twenty-one".