1987658406 has 24 divisors (see below), whose sum is σ = 4417746840. Its totient is φ = 662443596.

The previous prime is 1987658383. The next prime is 1987658441. The reversal of 1987658406 is 6048567891.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 324585 + ... + 330651.

It is an arithmetic number, because the mean of its divisors is an integer number (184072785).

Almost surely, 2^1987658406 is an apocalyptic number.

1987658406 is an abundant number, since it is smaller than the sum of its proper divisors (2430088434).

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

1987658406 is an frugal number, since it uses more digits than its factorization.

1987658406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12145 (or 6072 counting only the distinct ones).

The product of its (nonzero) digits is 2903040, while the sum is 54.

The square root of 1987658406 is about 44583.1628083966. The cubic root of 1987658406 is about 1257.3241285106.

Multiplying 1987658406 by its sum of digits (54), we get a square (107333553924 = 327618²).

1987658406 divided by its sum of digits (54) gives a square (36808489 = 6067²).

The spelling of 1987658406 in words is "one billion, nine hundred eighty-seven million, six hundred fifty-eight thousand, four hundred six".