63751921 has 4 divisors (see below), whose sum is σ = 67502052. Its totient is φ = 60001792.

The previous prime is 63751901. The next prime is 63751939. The reversal of 63751921 is 12915736.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 32615521 + 31136400 = 5711^2 + 5580^2 .

It is a cyclic number.

It is not a de Polignac number, because 63751921 - 2²³ = 55363313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (63751901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1875040 + ... + 1875073.

It is an arithmetic number, because the mean of its divisors is an integer number (16875513).

Almost surely, 2^63751921 is an apocalyptic number.

It is an amenable number.

63751921 is a deficient number, since it is larger than the sum of its proper divisors (3750131).

63751921 is a wasteful number, since it uses less digits than its factorization.

63751921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3750130.

The product of its digits is 11340, while the sum is 34.

The square root of 63751921 is about 7984.4800081157. The cubic root of 63751921 is about 399.4824995219.

The spelling of 63751921 in words is "sixty-three million, seven hundred fifty-one thousand, nine hundred twenty-one".