66550731 has 16 divisors (see below), whose sum is σ = 97595904. Its totient is φ = 40081824.

The previous prime is 66550721. The next prime is 66550741. The reversal of 66550731 is 13705566.

It is an interprime number because it is at equal distance from previous prime (66550721) and next prime (66550741).

It is not a de Polignac number, because 66550731 - 2⁹ = 66550219 is a prime.

It is a super-2 number, since 2×66550731² = 8857999593268722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66550692 and 66550701.

It is not an unprimeable number, because it can be changed into a prime (66550721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16321 + ... + 19986.

It is an arithmetic number, because the mean of its divisors is an integer number (6099744).

Almost surely, 2^66550731 is an apocalyptic number.

66550731 is a deficient number, since it is larger than the sum of its proper divisors (31045173).

66550731 is a wasteful number, since it uses less digits than its factorization.

66550731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36370.

The product of its (nonzero) digits is 18900, while the sum is 33.

The square root of 66550731 is about 8157.8631393276. The cubic root of 66550731 is about 405.2449486065.

The spelling of 66550731 in words is "sixty-six million, five hundred fifty thousand, seven hundred thirty-one".