61443921 has 24 divisors (see below), whose sum is σ = 102918592. Its totient is φ = 31917600.

The previous prime is 61443919. The next prime is 61443923. The reversal of 61443921 is 12934416.

It is an interprime number because it is at equal distance from previous prime (61443919) and next prime (61443923).

It is not a de Polignac number, because 61443921 - 2¹ = 61443919 is a prime.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (61443923) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9550 + ... + 14631.

Almost surely, 2^61443921 is an apocalyptic number.

It is an amenable number.

61443921 is a deficient number, since it is larger than the sum of its proper divisors (41474671).

61443921 is a wasteful number, since it uses less digits than its factorization.

61443921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24213 (or 24202 counting only the distinct ones).

The product of its digits is 5184, while the sum is 30.

The square root of 61443921 is about 7838.6172887825. The cubic root of 61443921 is about 394.6023258268.

The spelling of 61443921 in words is "sixty-one million, four hundred forty-three thousand, nine hundred twenty-one".