31421638 has 8 divisors (see below), whose sum is σ = 47162088. Its totient is φ = 15700944.

The previous prime is 31421623. The next prime is 31421641. The reversal of 31421638 is 83612413.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45 + ... + 7927.

It is an arithmetic number, because the mean of its divisors is an integer number (5895261).

Almost surely, 2^31421638 is an apocalyptic number.

31421638 is a deficient number, since it is larger than the sum of its proper divisors (15740450).

31421638 is a wasteful number, since it uses less digits than its factorization.

31421638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9878.

The product of its digits is 3456, while the sum is 28.

The square root of 31421638 is about 5605.5006912853. The cubic root of 31421638 is about 315.5558774619. Note that the first 3 decimals are identical.

It can be divided in two parts, 314 and 21638, that added together give a cube (21952 = 28³).

The spelling of 31421638 in words is "thirty-one million, four hundred twenty-one thousand, six hundred thirty-eight".