67421551 has 4 divisors (see below), whose sum is σ = 67482712. Its totient is φ = 67360392.

The previous prime is 67421539. The next prime is 67421567. The reversal of 67421551 is 15512476.

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

It is a cyclic number.

It is not a de Polignac number, because 67421551 - 2¹¹ = 67419503 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (67421521) 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, 28896 + ... + 31141.

It is an arithmetic number, because the mean of its divisors is an integer number (16870678).

Almost surely, 2^67421551 is an apocalyptic number.

67421551 is a deficient number, since it is larger than the sum of its proper divisors (61161).

67421551 is a wasteful number, since it uses less digits than its factorization.

67421551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61160.

The product of its digits is 8400, while the sum is 31.

The square root of 67421551 is about 8211.0627205009. The cubic root of 67421551 is about 407.0048455295.

The spelling of 67421551 in words is "sixty-seven million, four hundred twenty-one thousand, five hundred fifty-one".