638356490 has 32 divisors (see below), whose sum is σ = 1262113920. Its totient is φ = 231384384.

The previous prime is 638356487. The next prime is 638356501. The reversal of 638356490 is 94653836.

It is a super-3 number, since 3×638356490³ (a number of 27 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 68669 + ... + 77408.

It is an arithmetic number, because the mean of its divisors is an integer number (39441060).

Almost surely, 2^638356490 is an apocalyptic number.

638356490 is a deficient number, since it is larger than the sum of its proper divisors (623757430).

638356490 is a wasteful number, since it uses less digits than its factorization.

638356490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146126.

The product of its (nonzero) digits is 466560, while the sum is 44.

The square root of 638356490 is about 25265.7176822666. The cubic root of 638356490 is about 861.0355697158.

The spelling of 638356490 in words is "six hundred thirty-eight million, three hundred fifty-six thousand, four hundred ninety".