61400991 has 8 divisors (see below), whose sum is σ = 86683824. Its totient is φ = 38526080.

The previous prime is 61400981. The next prime is 61401001. The reversal of 61400991 is 19900416.

It is an interprime number because it is at equal distance from previous prime (61400981) and next prime (61401001).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 61400991 - 2¹⁰ = 61399967 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61400971) 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 in 7 ways as a sum of consecutive naturals, for example, 601920 + ... + 602021.

It is an arithmetic number, because the mean of its divisors is an integer number (10835478).

Almost surely, 2^61400991 is an apocalyptic number.

61400991 is a deficient number, since it is larger than the sum of its proper divisors (25282833).

61400991 is a wasteful number, since it uses less digits than its factorization.

61400991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1203961.

The product of its (nonzero) digits is 1944, while the sum is 30.

The square root of 61400991 is about 7835.8784446927. The cubic root of 61400991 is about 394.5104033907.

The spelling of 61400991 in words is "sixty-one million, four hundred thousand, nine hundred ninety-one".