39987990 has 48 divisors (see below), whose sum is σ = 118823328. Its totient is φ = 9139968.

The previous prime is 39987949. The next prime is 39988031. The reversal of 39987990 is 9978993.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (39987949) and next prime (39988031).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 31107 + ... + 32366.

It is an arithmetic number, because the mean of its divisors is an integer number (2475486).

Almost surely, 2^39987990 is an apocalyptic number.

39987990 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

39987990 is an abundant number, since it is smaller than the sum of its proper divisors (78835338).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

39987990 is a wasteful number, since it uses less digits than its factorization.

39987990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63493 (or 63490 counting only the distinct ones).

The product of its (nonzero) digits is 1102248, while the sum is 54.

The square root of 39987990 is about 6323.6057751887. The cubic root of 39987990 is about 341.9609578906.

It can be divided in two parts, 399 and 87990, that multiplied together give a triangular number (35108010 = T₈₃₇₉).

The spelling of 39987990 in words is "thirty-nine million, nine hundred eighty-seven thousand, nine hundred ninety".